zh/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html - iotdb-website - Git at Google

 <!DOCTYPE html>
 <html lang="zh-CN">
   <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width,initial-scale=1">
     <title> </title>
     <meta name="generator" content="VuePress 1.8.2">
     <link rel="icon" href="/favicon.ico">
     <meta name="description" content=" ">
     <meta name="Description" content="Apache IoTDB: Time Series Database for IoT">
     <meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据">
     <meta name="baidu-site-verification" content="wfKETzB3OT">
     <meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo">

     <link rel="preload" href="/assets/css/0.styles.ccadf850.css" as="style"><link rel="preload" href="/assets/js/app.2be61c67.js" as="script"><link rel="preload" href="/assets/js/3.76c26675.js" as="script"><link rel="preload" href="/assets/js/405.80826ea1.js" as="script"><link rel="prefetch" href="/assets/js/10.77e7d27b.js"><link rel="prefetch" href="/assets/js/100.5978c232.js"><link rel="prefetch" href="/assets/js/101.3c06894e.js"><link rel="prefetch" href="/assets/js/102.7005756d.js"><link rel="prefetch" href="/assets/js/103.911b070f.js"><link rel="prefetch" href="/assets/js/104.c42705fc.js"><link rel="prefetch" href="/assets/js/105.fc24900a.js"><link rel="prefetch" href="/assets/js/106.e2c7a612.js"><link rel="prefetch" href="/assets/js/107.1a274d23.js"><link rel="prefetch" href="/assets/js/108.f4b2f266.js"><link rel="prefetch" href="/assets/js/109.0dfdb183.js"><link rel="prefetch" href="/assets/js/11.c977ea47.js"><link rel="prefetch" href="/assets/js/110.c0cf66fd.js"><link rel="prefetch" href="/assets/js/111.ac7da683.js"><link rel="prefetch" href="/assets/js/112.fab622d7.js"><link rel="prefetch" href="/assets/js/113.8814f02a.js"><link rel="prefetch" href="/assets/js/114.1551f368.js"><link rel="prefetch" href="/assets/js/115.10ab0fa6.js"><link rel="prefetch" href="/assets/js/116.24d8e3ae.js"><link rel="prefetch" href="/assets/js/117.62b77e48.js"><link rel="prefetch" href="/assets/js/118.b5f4285f.js"><link rel="prefetch" href="/assets/js/119.289b64a7.js"><link rel="prefetch" href="/assets/js/12.643b0fb0.js"><link rel="prefetch" href="/assets/js/120.a3a7d6a6.js"><link rel="prefetch" href="/assets/js/121.5515c0ec.js"><link rel="prefetch" href="/assets/js/122.35cc367c.js"><link rel="prefetch" href="/assets/js/123.8060bcba.js"><link rel="prefetch" href="/assets/js/124.a437724f.js"><link rel="prefetch" href="/assets/js/125.7e0ae3d5.js"><link rel="prefetch" href="/assets/js/126.dfa5e587.js"><link rel="prefetch" href="/assets/js/127.82d22059.js"><link rel="prefetch" href="/assets/js/128.71d68503.js"><link rel="prefetch" href="/assets/js/129.b1d7b4ee.js"><link rel="prefetch" href="/assets/js/13.a4d58a0e.js"><link rel="prefetch" href="/assets/js/130.0e44556c.js"><link rel="prefetch" href="/assets/js/131.f49b82ba.js"><link rel="prefetch" href="/assets/js/132.2305a855.js"><link rel="prefetch" href="/assets/js/133.f2e444f9.js"><link rel="prefetch" href="/assets/js/134.8ce7ebe8.js"><link rel="prefetch" href="/assets/js/135.1c822c60.js"><link rel="prefetch" href="/assets/js/136.a3f695f3.js"><link rel="prefetch" href="/assets/js/137.14d95caa.js"><link rel="prefetch" href="/assets/js/138.d88ea14c.js"><link rel="prefetch" href="/assets/js/139.66718d11.js"><link rel="prefetch" href="/assets/js/14.4a4bedae.js"><link rel="prefetch" href="/assets/js/140.e38061b3.js"><link rel="prefetch" href="/assets/js/141.2acb2a1b.js"><link rel="prefetch" href="/assets/js/142.69da0d10.js"><link rel="prefetch" href="/assets/js/143.04577d6e.js"><link rel="prefetch" href="/assets/js/144.ccfd152f.js"><link rel="prefetch" href="/assets/js/145.834006ea.js"><link rel="prefetch" href="/assets/js/146.8a105652.js"><link rel="prefetch" href="/assets/js/147.c57e74c9.js"><link rel="prefetch" href="/assets/js/148.e749901c.js"><link rel="prefetch" href="/assets/js/149.c09d3abb.js"><link rel="prefetch" href="/assets/js/15.43bf9dc7.js"><link rel="prefetch" href="/assets/js/150.0cff15e0.js"><link rel="prefetch" href="/assets/js/151.13f45c22.js"><link rel="prefetch" href="/assets/js/152.cbece8f6.js"><link rel="prefetch" href="/assets/js/153.5fdc9dde.js"><link rel="prefetch" href="/assets/js/154.0b8e5442.js"><link rel="prefetch" href="/assets/js/155.b86990ed.js"><link rel="prefetch" href="/assets/js/156.eceb5d96.js"><link rel="prefetch" href="/assets/js/157.d1c61837.js"><link rel="prefetch" href="/assets/js/158.a06eb3ba.js"><link rel="prefetch" href="/assets/js/159.77ebe8da.js"><link rel="prefetch" href="/assets/js/16.8d99ed47.js"><link rel="prefetch" href="/assets/js/160.7dbd6018.js"><link rel="prefetch" href="/assets/js/161.b34e422b.js"><link rel="prefetch" href="/assets/js/162.650373ef.js"><link rel="prefetch" href="/assets/js/163.b75be02c.js"><link rel="prefetch" href="/assets/js/164.7b779ce2.js"><link rel="prefetch" href="/assets/js/165.dde20342.js"><link rel="prefetch" href="/assets/js/166.bdf54e36.js"><link rel="prefetch" href="/assets/js/167.e610df20.js"><link rel="prefetch" href="/assets/js/168.da12f653.js"><link rel="prefetch" href="/assets/js/169.a17b51a5.js"><link rel="prefetch" href="/assets/js/17.efe29df6.js"><link rel="prefetch" href="/assets/js/170.98aecdb5.js"><link rel="prefetch" href="/assets/js/171.38f40a14.js"><link rel="prefetch" href="/assets/js/172.568115a6.js"><link rel="prefetch" href="/assets/js/173.05d1b7cd.js"><link rel="prefetch" href="/assets/js/174.89bb943f.js"><link rel="prefetch" href="/assets/js/175.a15325e0.js"><link rel="prefetch" href="/assets/js/176.957205a1.js"><link rel="prefetch" href="/assets/js/177.342fa158.js"><link rel="prefetch" href="/assets/js/178.b1970e95.js"><link rel="prefetch" href="/assets/js/179.f20c8fcf.js"><link rel="prefetch" href="/assets/js/18.07265d0f.js"><link rel="prefetch" href="/assets/js/180.0b055cea.js"><link rel="prefetch" href="/assets/js/181.5463f34c.js"><link rel="prefetch" href="/assets/js/182.3f957446.js"><link rel="prefetch" href="/assets/js/183.9c026044.js"><link rel="prefetch" href="/assets/js/184.fb7c5cbf.js"><link rel="prefetch" href="/assets/js/185.5702ac62.js"><link rel="prefetch" href="/assets/js/186.9e7facfb.js"><link rel="prefetch" href="/assets/js/187.10d06549.js"><link rel="prefetch" href="/assets/js/188.163ae726.js"><link rel="prefetch" href="/assets/js/189.387099b2.js"><link rel="prefetch" href="/assets/js/19.e46591ce.js"><link rel="prefetch" href="/assets/js/190.a737b6d5.js"><link rel="prefetch" href="/assets/js/191.29303307.js"><link rel="prefetch" href="/assets/js/192.649843f1.js"><link rel="prefetch" href="/assets/js/193.b3388900.js"><link rel="prefetch" href="/assets/js/194.c69dc82e.js"><link rel="prefetch" href="/assets/js/195.5cfd6276.js"><link rel="prefetch" href="/assets/js/196.c0789301.js"><link rel="prefetch" href="/assets/js/197.24839fe1.js"><link rel="prefetch" href="/assets/js/198.32230f09.js"><link rel="prefetch" href="/assets/js/199.4649568f.js"><link rel="prefetch" href="/assets/js/20.cf088c3b.js"><link rel="prefetch" href="/assets/js/200.ecdc68bb.js"><link rel="prefetch" href="/assets/js/201.1adf86e1.js"><link rel="prefetch" href="/assets/js/202.354be9bb.js"><link rel="prefetch" href="/assets/js/203.91db71eb.js"><link rel="prefetch" href="/assets/js/204.c4fd1e7a.js"><link rel="prefetch" href="/assets/js/205.95368a99.js"><link rel="prefetch" href="/assets/js/206.83298a02.js"><link rel="prefetch" href="/assets/js/207.966b1c38.js"><link rel="prefetch" href="/assets/js/208.0f10808e.js"><link rel="prefetch" href="/assets/js/209.94083b01.js"><link rel="prefetch" href="/assets/js/21.7c4456b0.js"><link rel="prefetch" href="/assets/js/210.c73194ab.js"><link rel="prefetch" href="/assets/js/211.98653326.js"><link rel="prefetch" href="/assets/js/212.0bd8e759.js"><link rel="prefetch" href="/assets/js/213.50bedb05.js"><link rel="prefetch" href="/assets/js/214.388414b0.js"><link rel="prefetch" href="/assets/js/215.4ec26cc5.js"><link rel="prefetch" href="/assets/js/216.4daf4a2f.js"><link rel="prefetch" href="/assets/js/217.1db92b77.js"><link rel="prefetch" href="/assets/js/218.8c7c0ed3.js"><link rel="prefetch" href="/assets/js/219.071386e7.js"><link rel="prefetch" href="/assets/js/22.0d791f94.js"><link rel="prefetch" href="/assets/js/220.54ee8906.js"><link rel="prefetch" href="/assets/js/221.128f6cb4.js"><link rel="prefetch" href="/assets/js/222.37ce006e.js"><link rel="prefetch" href="/assets/js/223.a15a2f53.js"><link rel="prefetch" href="/assets/js/224.a9e8d08f.js"><link rel="prefetch" href="/assets/js/225.d4eee9f5.js"><link rel="prefetch" href="/assets/js/226.997ca0c2.js"><link rel="prefetch" href="/assets/js/227.741bef94.js"><link rel="prefetch" href="/assets/js/228.c3f1556b.js"><link rel="prefetch" href="/assets/js/229.1cd8821a.js"><link rel="prefetch" href="/assets/js/23.a479be57.js"><link rel="prefetch" href="/assets/js/230.ba6bcaf2.js"><link rel="prefetch" href="/assets/js/231.18bef6d1.js"><link rel="prefetch" href="/assets/js/232.083067e0.js"><link rel="prefetch" href="/assets/js/233.a690d5ae.js"><link rel="prefetch" href="/assets/js/234.01fe6899.js"><link rel="prefetch" href="/assets/js/235.eb70513e.js"><link rel="prefetch" href="/assets/js/236.5a9113d6.js"><link rel="prefetch" href="/assets/js/237.99203a50.js"><link rel="prefetch" href="/assets/js/238.f90f1f07.js"><link rel="prefetch" href="/assets/js/239.f0bcd461.js"><link rel="prefetch" href="/assets/js/24.de37758e.js"><link rel="prefetch" href="/assets/js/240.2a401737.js"><link rel="prefetch" href="/assets/js/241.5858d35e.js"><link rel="prefetch" href="/assets/js/242.b260464e.js"><link rel="prefetch" href="/assets/js/243.96540218.js"><link rel="prefetch" href="/assets/js/244.c47dc56c.js"><link rel="prefetch" href="/assets/js/245.3852d8dd.js"><link rel="prefetch" href="/assets/js/246.f6d16cb9.js"><link rel="prefetch" href="/assets/js/247.039d13fd.js"><link rel="prefetch" href="/assets/js/248.9536ebc1.js"><link rel="prefetch" href="/assets/js/249.0e58249a.js"><link rel="prefetch" href="/assets/js/25.77e4633a.js"><link rel="prefetch" href="/assets/js/250.dfcb233f.js"><link rel="prefetch" href="/assets/js/251.40e9e79a.js"><link rel="prefetch" href="/assets/js/252.ff6ab14e.js"><link rel="prefetch" href="/assets/js/253.9c2ec16e.js"><link rel="prefetch" href="/assets/js/254.df494a1c.js"><link rel="prefetch" href="/assets/js/255.cfab9f22.js"><link rel="prefetch" href="/assets/js/256.3f62947f.js"><link rel="prefetch" href="/assets/js/257.4a4b953b.js"><link rel="prefetch" href="/assets/js/258.9da81847.js"><link rel="prefetch" href="/assets/js/259.9a890b58.js"><link rel="prefetch" href="/assets/js/26.bc913725.js"><link rel="prefetch" href="/assets/js/260.25059a8b.js"><link rel="prefetch" href="/assets/js/261.b46c4c45.js"><link rel="prefetch" href="/assets/js/262.a7c40553.js"><link rel="prefetch" href="/assets/js/263.6bf75f17.js"><link rel="prefetch" href="/assets/js/264.8d95fd19.js"><link rel="prefetch" href="/assets/js/265.70d8d0d0.js"><link rel="prefetch" href="/assets/js/266.6f7c78a6.js"><link rel="prefetch" href="/assets/js/267.3a11b8f6.js"><link rel="prefetch" href="/assets/js/268.53499932.js"><link rel="prefetch" href="/assets/js/269.a1b4a38e.js"><link rel="prefetch" href="/assets/js/27.ce2cad14.js"><link rel="prefetch" href="/assets/js/270.0ff1ebdc.js"><link rel="prefetch" href="/assets/js/271.5cda34f0.js"><link rel="prefetch" href="/assets/js/272.357c1eee.js"><link rel="prefetch" href="/assets/js/273.db93948e.js"><link rel="prefetch" href="/assets/js/274.2c8e7fe4.js"><link rel="prefetch" href="/assets/js/275.8a6fbd0d.js"><link rel="prefetch" href="/assets/js/276.34f2423f.js"><link rel="prefetch" href="/assets/js/277.19f66113.js"><link rel="prefetch" href="/assets/js/278.88fc788e.js"><link rel="prefetch" href="/assets/js/279.1c91a92e.js"><link rel="prefetch" href="/assets/js/28.196d9118.js"><link rel="prefetch" href="/assets/js/280.0d760d52.js"><link rel="prefetch" href="/assets/js/281.f7f5aa4d.js"><link rel="prefetch" href="/assets/js/282.7e6328e3.js"><link rel="prefetch" href="/assets/js/283.0232ecfb.js"><link rel="prefetch" href="/assets/js/284.9c6d661e.js"><link rel="prefetch" href="/assets/js/285.4efd3863.js"><link rel="prefetch" href="/assets/js/286.a7cf806d.js"><link rel="prefetch" href="/assets/js/287.cad93c83.js"><link rel="prefetch" href="/assets/js/288.2cdaca3b.js"><link rel="prefetch" href="/assets/js/289.8f217264.js"><link rel="prefetch" href="/assets/js/29.91dc2824.js"><link rel="prefetch" href="/assets/js/290.dafc66d9.js"><link rel="prefetch" href="/assets/js/291.22a9e6bd.js"><link rel="prefetch" href="/assets/js/292.deeefef9.js"><link rel="prefetch" href="/assets/js/293.b7fa5dd0.js"><link rel="prefetch" href="/assets/js/294.884ba36d.js"><link rel="prefetch" href="/assets/js/295.0f7d1349.js"><link rel="prefetch" href="/assets/js/296.b41c6aaf.js"><link rel="prefetch" href="/assets/js/297.cb35a816.js"><link rel="prefetch" href="/assets/js/298.10f5b520.js"><link rel="prefetch" href="/assets/js/299.ba763072.js"><link rel="prefetch" href="/assets/js/30.60649b66.js"><link rel="prefetch" href="/assets/js/300.503d67a6.js"><link rel="prefetch" href="/assets/js/301.bd8b07a8.js"><link rel="prefetch" href="/assets/js/302.d34579a2.js"><link rel="prefetch" href="/assets/js/303.75b9c998.js"><link rel="prefetch" href="/assets/js/304.a0d9bd1e.js"><link rel="prefetch" href="/assets/js/305.b920fdf6.js"><link rel="prefetch" href="/assets/js/306.103f06d3.js"><link rel="prefetch" href="/assets/js/307.5cd94467.js"><link rel="prefetch" href="/assets/js/308.551b2e96.js"><link rel="prefetch" href="/assets/js/309.6c393e75.js"><link rel="prefetch" href="/assets/js/31.fab44020.js"><link rel="prefetch" href="/assets/js/310.13d1174d.js"><link rel="prefetch" href="/assets/js/311.6390b351.js"><link rel="prefetch" href="/assets/js/312.e4441d29.js"><link rel="prefetch" href="/assets/js/313.5045008e.js"><link rel="prefetch" href="/assets/js/314.d02b9a2a.js"><link rel="prefetch" href="/assets/js/315.f9c85cb2.js"><link rel="prefetch" href="/assets/js/316.f277f043.js"><link rel="prefetch" href="/assets/js/317.ec54a9fa.js"><link rel="prefetch" href="/assets/js/318.a17c5fdc.js"><link rel="prefetch" href="/assets/js/319.18a9e9ec.js"><link rel="prefetch" href="/assets/js/32.e5e702b0.js"><link rel="prefetch" href="/assets/js/320.c8af7744.js"><link rel="prefetch" href="/assets/js/321.fd9f73db.js"><link rel="prefetch" href="/assets/js/322.a5716fc9.js"><link rel="prefetch" href="/assets/js/323.f8103e09.js"><link rel="prefetch" href="/assets/js/324.6a332a88.js"><link rel="prefetch" href="/assets/js/325.0cbe8f4f.js"><link rel="prefetch" href="/assets/js/326.93fceca1.js"><link rel="prefetch" href="/assets/js/327.9ce809fe.js"><link rel="prefetch" href="/assets/js/328.fca2d6a0.js"><link rel="prefetch" href="/assets/js/329.1282a9c1.js"><link rel="prefetch" href="/assets/js/33.b678d537.js"><link rel="prefetch" href="/assets/js/330.13adf005.js"><link rel="prefetch" href="/assets/js/331.d6d115cc.js"><link rel="prefetch" href="/assets/js/332.d32d6427.js"><link rel="prefetch" href="/assets/js/333.de101422.js"><link rel="prefetch" href="/assets/js/334.e87a7cc5.js"><link rel="prefetch" href="/assets/js/335.c6847516.js"><link rel="prefetch" href="/assets/js/336.f6fed1c6.js"><link rel="prefetch" href="/assets/js/337.37ed96cd.js"><link rel="prefetch" href="/assets/js/338.2d943262.js"><link rel="prefetch" href="/assets/js/339.3443bd0c.js"><link rel="prefetch" href="/assets/js/34.7b065e16.js"><link rel="prefetch" href="/assets/js/340.1b05c70f.js"><link rel="prefetch" href="/assets/js/341.bf0f9508.js"><link rel="prefetch" href="/assets/js/342.3fbdaee0.js"><link rel="prefetch" href="/assets/js/343.630a495e.js"><link rel="prefetch" href="/assets/js/344.a234a73f.js"><link rel="prefetch" href="/assets/js/345.b2ce2372.js"><link rel="prefetch" href="/assets/js/346.bfc24599.js"><link rel="prefetch" href="/assets/js/347.25473fe5.js"><link rel="prefetch" href="/assets/js/348.f01ca0ff.js"><link rel="prefetch" href="/assets/js/349.e8ff6c21.js"><link rel="prefetch" href="/assets/js/35.79f48bad.js"><link rel="prefetch" href="/assets/js/350.64aa3024.js"><link rel="prefetch" href="/assets/js/351.616b18a1.js"><link rel="prefetch" href="/assets/js/352.527b817a.js"><link rel="prefetch" href="/assets/js/353.fc4255eb.js"><link rel="prefetch" href="/assets/js/354.28952833.js"><link rel="prefetch" href="/assets/js/355.b20b5864.js"><link rel="prefetch" href="/assets/js/356.eb081931.js"><link rel="prefetch" href="/assets/js/357.daea00ab.js"><link rel="prefetch" href="/assets/js/358.7de0afb3.js"><link rel="prefetch" href="/assets/js/359.a722d835.js"><link rel="prefetch" href="/assets/js/36.4e36f97e.js"><link rel="prefetch" href="/assets/js/360.cc3f9eff.js"><link rel="prefetch" href="/assets/js/361.957b907a.js"><link rel="prefetch" href="/assets/js/362.05464ead.js"><link rel="prefetch" href="/assets/js/363.dcc13548.js"><link rel="prefetch" href="/assets/js/364.2c2529a1.js"><link rel="prefetch" href="/assets/js/365.ccde8473.js"><link rel="prefetch" href="/assets/js/366.bbf0ce04.js"><link rel="prefetch" href="/assets/js/367.c5aafff8.js"><link rel="prefetch" href="/assets/js/368.7d23c4e6.js"><link rel="prefetch" href="/assets/js/369.0f424e1d.js"><link rel="prefetch" href="/assets/js/37.33185238.js"><link rel="prefetch" href="/assets/js/370.e98b0418.js"><link rel="prefetch" href="/assets/js/371.6eb4cf9f.js"><link rel="prefetch" href="/assets/js/372.2141c416.js"><link rel="prefetch" href="/assets/js/373.25685ada.js"><link rel="prefetch" href="/assets/js/374.3ce6d66c.js"><link rel="prefetch" href="/assets/js/375.dc904417.js"><link rel="prefetch" href="/assets/js/376.fde1e3d3.js"><link rel="prefetch" href="/assets/js/377.a1d2f194.js"><link rel="prefetch" href="/assets/js/378.88128618.js"><link rel="prefetch" href="/assets/js/379.a5d1aca5.js"><link rel="prefetch" href="/assets/js/38.b02b6af6.js"><link rel="prefetch" href="/assets/js/380.e9a0a3e4.js"><link rel="prefetch" href="/assets/js/381.cbc420d0.js"><link rel="prefetch" href="/assets/js/382.27942c5e.js"><link rel="prefetch" href="/assets/js/383.2042e12b.js"><link rel="prefetch" href="/assets/js/384.69f48d6e.js"><link rel="prefetch" href="/assets/js/385.450c0692.js"><link rel="prefetch" href="/assets/js/386.d1bb1e30.js"><link rel="prefetch" href="/assets/js/387.cd639bfa.js"><link rel="prefetch" href="/assets/js/388.4690fa6f.js"><link rel="prefetch" href="/assets/js/389.c3ad621a.js"><link rel="prefetch" href="/assets/js/39.2861d4e5.js"><link rel="prefetch" href="/assets/js/390.cd84bb90.js"><link rel="prefetch" href="/assets/js/391.cdb6768a.js"><link rel="prefetch" href="/assets/js/392.3304f571.js"><link rel="prefetch" href="/assets/js/393.a91e77e8.js"><link rel="prefetch" href="/assets/js/394.f99051fd.js"><link rel="prefetch" href="/assets/js/395.9c2f85cb.js"><link rel="prefetch" href="/assets/js/396.734c3f15.js"><link rel="prefetch" href="/assets/js/397.eb3cb411.js"><link rel="prefetch" href="/assets/js/398.21324d16.js"><link rel="prefetch" href="/assets/js/399.e5613041.js"><link rel="prefetch" href="/assets/js/4.860a5721.js"><link rel="prefetch" href="/assets/js/40.6f6fb483.js"><link rel="prefetch" href="/assets/js/400.f37f241a.js"><link rel="prefetch" href="/assets/js/401.6c60fdd3.js"><link rel="prefetch" href="/assets/js/402.b4ef1603.js"><link rel="prefetch" href="/assets/js/403.264594b0.js"><link rel="prefetch" href="/assets/js/404.b09fba9e.js"><link rel="prefetch" href="/assets/js/406.73631b7f.js"><link rel="prefetch" href="/assets/js/407.5acbdf9e.js"><link rel="prefetch" href="/assets/js/408.67447621.js"><link rel="prefetch" href="/assets/js/409.4d398928.js"><link rel="prefetch" href="/assets/js/41.54dfae4f.js"><link rel="prefetch" href="/assets/js/410.cd6ef2d8.js"><link rel="prefetch" href="/assets/js/411.1cc06de8.js"><link rel="prefetch" href="/assets/js/412.bbf05dd5.js"><link rel="prefetch" href="/assets/js/413.b8bb4544.js"><link rel="prefetch" href="/assets/js/414.92349085.js"><link rel="prefetch" href="/assets/js/415.989628a8.js"><link rel="prefetch" href="/assets/js/416.c371deaf.js"><link rel="prefetch" href="/assets/js/417.28c30f8d.js"><link rel="prefetch" href="/assets/js/418.5d9468fc.js"><link rel="prefetch" href="/assets/js/419.fe0c2dcb.js"><link rel="prefetch" href="/assets/js/42.634cb345.js"><link rel="prefetch" href="/assets/js/420.35071d8d.js"><link rel="prefetch" href="/assets/js/421.c7405cb6.js"><link rel="prefetch" href="/assets/js/422.1994ad42.js"><link rel="prefetch" href="/assets/js/423.a26dc674.js"><link rel="prefetch" href="/assets/js/424.27381d5f.js"><link rel="prefetch" href="/assets/js/425.f2994924.js"><link rel="prefetch" href="/assets/js/426.acf56e67.js"><link rel="prefetch" href="/assets/js/427.d4736e32.js"><link rel="prefetch" href="/assets/js/428.bbd6f000.js"><link rel="prefetch" href="/assets/js/429.33d076f9.js"><link rel="prefetch" href="/assets/js/43.3fff5a4c.js"><link rel="prefetch" href="/assets/js/430.28361236.js"><link rel="prefetch" href="/assets/js/431.b20e093d.js"><link rel="prefetch" href="/assets/js/432.1c754e22.js"><link rel="prefetch" href="/assets/js/433.c0edf7c8.js"><link rel="prefetch" href="/assets/js/434.2bd857ef.js"><link rel="prefetch" href="/assets/js/435.11eb586d.js"><link rel="prefetch" href="/assets/js/436.f86ee01e.js"><link rel="prefetch" href="/assets/js/437.62cf3d26.js"><link rel="prefetch" href="/assets/js/438.d9dc7073.js"><link rel="prefetch" href="/assets/js/439.d36e71dd.js"><link rel="prefetch" href="/assets/js/44.048e5262.js"><link rel="prefetch" href="/assets/js/440.61cf1b86.js"><link rel="prefetch" href="/assets/js/441.0ae13653.js"><link rel="prefetch" href="/assets/js/442.8d0ee2a8.js"><link rel="prefetch" href="/assets/js/443.225d3dbb.js"><link rel="prefetch" href="/assets/js/444.626271de.js"><link rel="prefetch" href="/assets/js/445.2272a7fc.js"><link rel="prefetch" href="/assets/js/446.91a57cb6.js"><link rel="prefetch" href="/assets/js/447.222ebc6a.js"><link rel="prefetch" href="/assets/js/448.868cf1f8.js"><link rel="prefetch" href="/assets/js/449.b093edb6.js"><link rel="prefetch" href="/assets/js/45.3161e71b.js"><link rel="prefetch" href="/assets/js/450.c074c9a4.js"><link rel="prefetch" href="/assets/js/451.f6f35b11.js"><link rel="prefetch" href="/assets/js/452.7e778ff7.js"><link rel="prefetch" href="/assets/js/453.67b59c96.js"><link rel="prefetch" href="/assets/js/454.b5ed7647.js"><link rel="prefetch" href="/assets/js/455.55045395.js"><link rel="prefetch" href="/assets/js/456.249f166b.js"><link rel="prefetch" href="/assets/js/457.ac8fcf0d.js"><link rel="prefetch" href="/assets/js/458.fff99426.js"><link rel="prefetch" href="/assets/js/459.8f32e619.js"><link rel="prefetch" href="/assets/js/46.520cacec.js"><link rel="prefetch" href="/assets/js/460.7447567b.js"><link rel="prefetch" href="/assets/js/461.6178bddb.js"><link rel="prefetch" href="/assets/js/462.f60696a1.js"><link rel="prefetch" href="/assets/js/463.309f8ecc.js"><link rel="prefetch" href="/assets/js/464.35bb2621.js"><link rel="prefetch" href="/assets/js/465.3e82a4cf.js"><link rel="prefetch" href="/assets/js/466.337260a9.js"><link rel="prefetch" href="/assets/js/467.24d42d9b.js"><link rel="prefetch" href="/assets/js/468.2cc44636.js"><link rel="prefetch" href="/assets/js/469.9d75c005.js"><link rel="prefetch" href="/assets/js/47.a8742825.js"><link rel="prefetch" href="/assets/js/470.1a3ca4a6.js"><link rel="prefetch" href="/assets/js/471.745c8bf2.js"><link rel="prefetch" href="/assets/js/472.c857fa3d.js"><link rel="prefetch" href="/assets/js/473.036c7be4.js"><link rel="prefetch" href="/assets/js/474.29cdec0b.js"><link rel="prefetch" href="/assets/js/475.2fe78431.js"><link rel="prefetch" href="/assets/js/476.2b7ce637.js"><link rel="prefetch" href="/assets/js/477.e489e2d7.js"><link rel="prefetch" href="/assets/js/478.28446bd6.js"><link rel="prefetch" href="/assets/js/479.aca7b0ce.js"><link rel="prefetch" href="/assets/js/48.ad2c2a29.js"><link rel="prefetch" href="/assets/js/480.c2ed2c9b.js"><link rel="prefetch" href="/assets/js/481.604be7ca.js"><link rel="prefetch" href="/assets/js/482.e0217f30.js"><link rel="prefetch" href="/assets/js/483.cdda9e85.js"><link rel="prefetch" href="/assets/js/484.10f2fb22.js"><link rel="prefetch" href="/assets/js/485.2295bfa7.js"><link rel="prefetch" href="/assets/js/486.e561507a.js"><link rel="prefetch" href="/assets/js/487.06cca38a.js"><link rel="prefetch" href="/assets/js/488.2169a5df.js"><link rel="prefetch" href="/assets/js/489.8ef30aea.js"><link rel="prefetch" href="/assets/js/49.a22d6593.js"><link rel="prefetch" href="/assets/js/490.a6e9f99d.js"><link rel="prefetch" href="/assets/js/491.e078ec7a.js"><link rel="prefetch" href="/assets/js/492.ecd04f27.js"><link rel="prefetch" href="/assets/js/493.a35cbc4b.js"><link rel="prefetch" href="/assets/js/494.d66239f8.js"><link rel="prefetch" href="/assets/js/495.a389c93a.js"><link rel="prefetch" href="/assets/js/496.818b7047.js"><link rel="prefetch" href="/assets/js/497.cb70ba2c.js"><link rel="prefetch" href="/assets/js/498.f81d35f6.js"><link rel="prefetch" href="/assets/js/499.39ec261c.js"><link rel="prefetch" href="/assets/js/5.2a4451ec.js"><link rel="prefetch" href="/assets/js/50.abf20f4e.js"><link rel="prefetch" href="/assets/js/500.8a883e28.js"><link rel="prefetch" href="/assets/js/501.210aa35e.js"><link rel="prefetch" href="/assets/js/502.0a3d947f.js"><link rel="prefetch" href="/assets/js/503.d1e67738.js"><link rel="prefetch" href="/assets/js/504.f30f9c70.js"><link rel="prefetch" href="/assets/js/505.feadbbe8.js"><link rel="prefetch" href="/assets/js/506.67ce6593.js"><link rel="prefetch" href="/assets/js/507.6161dd8b.js"><link rel="prefetch" href="/assets/js/508.164ed528.js"><link rel="prefetch" href="/assets/js/509.39243cfc.js"><link rel="prefetch" href="/assets/js/51.65940de1.js"><link rel="prefetch" href="/assets/js/510.fc047f5d.js"><link rel="prefetch" href="/assets/js/511.dc5e0cf8.js"><link rel="prefetch" href="/assets/js/512.9accfd9f.js"><link rel="prefetch" href="/assets/js/513.77fdc498.js"><link rel="prefetch" href="/assets/js/514.7516bfbb.js"><link rel="prefetch" href="/assets/js/515.ec7ac327.js"><link rel="prefetch" href="/assets/js/516.7cafda3f.js"><link rel="prefetch" href="/assets/js/517.8afd51dc.js"><link rel="prefetch" href="/assets/js/518.ff7c1632.js"><link rel="prefetch" href="/assets/js/519.a1af4eb5.js"><link rel="prefetch" href="/assets/js/52.10d8a15b.js"><link rel="prefetch" href="/assets/js/520.5bd3028e.js"><link rel="prefetch" href="/assets/js/521.ff064e49.js"><link rel="prefetch" href="/assets/js/522.b53bbb3b.js"><link rel="prefetch" href="/assets/js/523.65fdc05c.js"><link rel="prefetch" href="/assets/js/524.9227e482.js"><link rel="prefetch" href="/assets/js/525.1c5a16f9.js"><link rel="prefetch" href="/assets/js/526.ba58a6d9.js"><link rel="prefetch" href="/assets/js/527.b8cafc93.js"><link rel="prefetch" href="/assets/js/528.19bf3e90.js"><link rel="prefetch" href="/assets/js/529.5e69e74b.js"><link rel="prefetch" href="/assets/js/53.41dd4d57.js"><link rel="prefetch" href="/assets/js/530.6f09a805.js"><link rel="prefetch" href="/assets/js/531.f418e38a.js"><link rel="prefetch" href="/assets/js/532.5b4a65b8.js"><link rel="prefetch" href="/assets/js/533.8de3ac38.js"><link rel="prefetch" href="/assets/js/534.7ee1d41c.js"><link rel="prefetch" href="/assets/js/535.e44544a1.js"><link rel="prefetch" href="/assets/js/536.29b5aa38.js"><link rel="prefetch" href="/assets/js/537.d880085c.js"><link rel="prefetch" href="/assets/js/538.fd8739e4.js"><link rel="prefetch" href="/assets/js/539.5ea286ba.js"><link rel="prefetch" href="/assets/js/54.2bd5a2fe.js"><link rel="prefetch" href="/assets/js/540.9157430c.js"><link rel="prefetch" href="/assets/js/541.d020594e.js"><link rel="prefetch" href="/assets/js/542.9569e347.js"><link rel="prefetch" href="/assets/js/543.d11b2a46.js"><link rel="prefetch" href="/assets/js/544.f394480d.js"><link rel="prefetch" href="/assets/js/545.0df80452.js"><link rel="prefetch" href="/assets/js/546.3a77b244.js"><link rel="prefetch" href="/assets/js/547.73300ff7.js"><link rel="prefetch" href="/assets/js/548.e5e54634.js"><link rel="prefetch" href="/assets/js/549.79c75623.js"><link rel="prefetch" href="/assets/js/55.a34d087b.js"><link rel="prefetch" href="/assets/js/550.6a5a01ca.js"><link rel="prefetch" href="/assets/js/551.2ab6cbb6.js"><link rel="prefetch" href="/assets/js/552.a523c03a.js"><link rel="prefetch" href="/assets/js/553.1e63e087.js"><link rel="prefetch" href="/assets/js/554.9079ff78.js"><link rel="prefetch" href="/assets/js/555.76e63349.js"><link rel="prefetch" href="/assets/js/556.69ade81b.js"><link rel="prefetch" href="/assets/js/557.837960af.js"><link rel="prefetch" href="/assets/js/558.27600996.js"><link rel="prefetch" href="/assets/js/559.51850cf1.js"><link rel="prefetch" href="/assets/js/56.a777e897.js"><link rel="prefetch" href="/assets/js/560.ab9ce7f9.js"><link rel="prefetch" href="/assets/js/561.9c4674ce.js"><link rel="prefetch" href="/assets/js/562.bcbfdf06.js"><link rel="prefetch" href="/assets/js/563.30537cf9.js"><link rel="prefetch" href="/assets/js/564.f56ad01f.js"><link rel="prefetch" href="/assets/js/565.8d8c028e.js"><link rel="prefetch" href="/assets/js/566.fd34dd08.js"><link rel="prefetch" href="/assets/js/567.ec6cc4fb.js"><link rel="prefetch" href="/assets/js/568.cd5b6590.js"><link rel="prefetch" href="/assets/js/569.16f9ec30.js"><link rel="prefetch" href="/assets/js/57.d5881d85.js"><link rel="prefetch" href="/assets/js/570.0674fef1.js"><link rel="prefetch" href="/assets/js/571.57d5e690.js"><link rel="prefetch" href="/assets/js/572.8c9e0a9e.js"><link rel="prefetch" href="/assets/js/573.a34f1c58.js"><link rel="prefetch" href="/assets/js/574.979d6170.js"><link rel="prefetch" href="/assets/js/575.d413f4e9.js"><link rel="prefetch" href="/assets/js/576.074b1d78.js"><link rel="prefetch" href="/assets/js/577.94e95ba8.js"><link rel="prefetch" href="/assets/js/578.7d3112d5.js"><link rel="prefetch" href="/assets/js/579.90f3005d.js"><link rel="prefetch" href="/assets/js/58.449bd56c.js"><link rel="prefetch" href="/assets/js/580.c8b424fb.js"><link rel="prefetch" href="/assets/js/581.d0145db3.js"><link rel="prefetch" href="/assets/js/582.cf02f385.js"><link rel="prefetch" href="/assets/js/583.ddea5b0d.js"><link rel="prefetch" href="/assets/js/584.0cc16d34.js"><link rel="prefetch" href="/assets/js/585.c447391d.js"><link rel="prefetch" href="/assets/js/586.df4eb9cd.js"><link rel="prefetch" href="/assets/js/587.10ee1879.js"><link rel="prefetch" href="/assets/js/588.f786f72b.js"><link rel="prefetch" href="/assets/js/589.c9585b6b.js"><link rel="prefetch" href="/assets/js/59.cec8b8e4.js"><link rel="prefetch" href="/assets/js/590.d58f3b92.js"><link rel="prefetch" href="/assets/js/591.5a7ede8d.js"><link rel="prefetch" href="/assets/js/592.37f408d3.js"><link rel="prefetch" href="/assets/js/593.4a806bb2.js"><link rel="prefetch" href="/assets/js/594.ed84c146.js"><link rel="prefetch" href="/assets/js/595.aa601bb0.js"><link rel="prefetch" href="/assets/js/596.a9c41a4f.js"><link rel="prefetch" href="/assets/js/597.5ebbba13.js"><link rel="prefetch" href="/assets/js/598.722f0a31.js"><link rel="prefetch" href="/assets/js/599.f307ce76.js"><link rel="prefetch" href="/assets/js/6.3450075a.js"><link rel="prefetch" href="/assets/js/60.31ea992e.js"><link rel="prefetch" href="/assets/js/600.61541c2b.js"><link rel="prefetch" href="/assets/js/601.d52d2580.js"><link rel="prefetch" href="/assets/js/602.07430208.js"><link rel="prefetch" href="/assets/js/603.0c6627b1.js"><link rel="prefetch" href="/assets/js/604.cfbfb4a9.js"><link rel="prefetch" href="/assets/js/605.307c2315.js"><link rel="prefetch" href="/assets/js/606.69523bf2.js"><link rel="prefetch" href="/assets/js/607.7fd1d0a9.js"><link rel="prefetch" href="/assets/js/608.8ac54eac.js"><link rel="prefetch" href="/assets/js/609.16ee9d18.js"><link rel="prefetch" href="/assets/js/61.91f8be9a.js"><link rel="prefetch" href="/assets/js/610.2696081c.js"><link rel="prefetch" href="/assets/js/611.cae8d15d.js"><link rel="prefetch" href="/assets/js/612.a7bbdb33.js"><link rel="prefetch" href="/assets/js/613.08525f49.js"><link rel="prefetch" href="/assets/js/614.d0a55e44.js"><link rel="prefetch" href="/assets/js/615.3f880d36.js"><link rel="prefetch" href="/assets/js/616.0f37f207.js"><link rel="prefetch" href="/assets/js/617.193d4902.js"><link rel="prefetch" href="/assets/js/618.0a95355e.js"><link rel="prefetch" href="/assets/js/619.a924c9b4.js"><link rel="prefetch" href="/assets/js/62.3c4e16b5.js"><link rel="prefetch" href="/assets/js/620.cee30d3f.js"><link rel="prefetch" href="/assets/js/621.49ab2c91.js"><link rel="prefetch" href="/assets/js/622.e7e619c4.js"><link rel="prefetch" href="/assets/js/623.3ef92ba2.js"><link rel="prefetch" href="/assets/js/624.f1d3238c.js"><link rel="prefetch" href="/assets/js/625.8a7a0611.js"><link rel="prefetch" href="/assets/js/626.9fd1ae19.js"><link rel="prefetch" href="/assets/js/627.57fca9fe.js"><link rel="prefetch" href="/assets/js/628.e2fd2c22.js"><link rel="prefetch" href="/assets/js/629.33c8405c.js"><link rel="prefetch" href="/assets/js/63.69f68e44.js"><link rel="prefetch" href="/assets/js/630.93c80187.js"><link rel="prefetch" href="/assets/js/631.bcc9f91f.js"><link rel="prefetch" href="/assets/js/632.4c5bd02a.js"><link rel="prefetch" href="/assets/js/633.75b73d02.js"><link rel="prefetch" href="/assets/js/634.028194f5.js"><link rel="prefetch" href="/assets/js/635.402943df.js"><link rel="prefetch" href="/assets/js/64.532ee46c.js"><link rel="prefetch" href="/assets/js/65.9e1f4290.js"><link rel="prefetch" href="/assets/js/66.ef2b4bb7.js"><link rel="prefetch" href="/assets/js/67.ab638ddc.js"><link rel="prefetch" href="/assets/js/68.62a1c4cf.js"><link rel="prefetch" href="/assets/js/69.c132ecf9.js"><link rel="prefetch" href="/assets/js/7.c5c54fb4.js"><link rel="prefetch" href="/assets/js/70.b43d79a7.js"><link rel="prefetch" href="/assets/js/71.add13364.js"><link rel="prefetch" href="/assets/js/72.adeb9caa.js"><link rel="prefetch" href="/assets/js/73.b1be9b18.js"><link rel="prefetch" href="/assets/js/74.46aa5512.js"><link rel="prefetch" href="/assets/js/75.61eca3de.js"><link rel="prefetch" href="/assets/js/76.cc2802e3.js"><link rel="prefetch" href="/assets/js/77.da24f38b.js"><link rel="prefetch" href="/assets/js/78.79bf9aa4.js"><link rel="prefetch" href="/assets/js/79.df11952f.js"><link rel="prefetch" href="/assets/js/8.de5c69e7.js"><link rel="prefetch" href="/assets/js/80.f29ee9a2.js"><link rel="prefetch" href="/assets/js/81.2b450674.js"><link rel="prefetch" href="/assets/js/82.13156504.js"><link rel="prefetch" href="/assets/js/83.e34d7844.js"><link rel="prefetch" href="/assets/js/84.a4c96ab7.js"><link rel="prefetch" href="/assets/js/85.0e71a3b0.js"><link rel="prefetch" href="/assets/js/86.0d2efd89.js"><link rel="prefetch" href="/assets/js/87.a1c4012a.js"><link rel="prefetch" href="/assets/js/88.3b2b71b6.js"><link rel="prefetch" href="/assets/js/89.5e5f9607.js"><link rel="prefetch" href="/assets/js/9.0b79e972.js"><link rel="prefetch" href="/assets/js/90.06a25bc1.js"><link rel="prefetch" href="/assets/js/91.2a338135.js"><link rel="prefetch" href="/assets/js/92.0834e685.js"><link rel="prefetch" href="/assets/js/93.b8060089.js"><link rel="prefetch" href="/assets/js/94.53d4ddf9.js"><link rel="prefetch" href="/assets/js/95.880645ca.js"><link rel="prefetch" href="/assets/js/96.2e0241dd.js"><link rel="prefetch" href="/assets/js/97.044c63a1.js"><link rel="prefetch" href="/assets/js/98.fa8e7351.js"><link rel="prefetch" href="/assets/js/99.b510a111.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.eff714eb.js">
     <link rel="stylesheet" href="/assets/css/0.styles.ccadf850.css">
   </head>
   <body>
     <div id="app" data-server-rendered="true"><div class="theme-container"><header class="navbar"><div class="sidebar-button"><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" role="img" viewBox="0 0 448 512" class="icon"><path fill="currentColor" d="M436 124H12c-6.627 0-12-5.373-12-12V80c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12z"></path></svg></div> <a href="/zh/" class="home-link router-link-active"><img src="/img/logo.png" alt=" " class="logo"></a> <div class="links"><div class="search-box"><input aria-label="Search" autocomplete="off" spellcheck="false" value=""> <!----></div> <nav class="nav-links can-hide"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">文档</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external">
   Wiki
   <!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external">
   基金会
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external">
   许可证
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external">
   安全
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external">
   赞助
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external">
   致谢
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external">
   活动
   <!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html" aria-current="page" class="nav-link router-link-exact-active router-link-active">简体中文</a></li></ul></div></div> <a href="https://github.com/apache/iotdb.git" target="_blank" rel="noopener noreferrer" class="repo-link">
     gitHub
     <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav></div></header> <div class="sidebar-mask"></div> <aside class="sidebar"><nav class="nav-links"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">文档</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external">
   Wiki
   <!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external">
   基金会
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external">
   许可证
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external">
   安全
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external">
   赞助
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external">
   致谢
   <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external">
   活动
   <!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html" aria-current="page" class="nav-link router-link-exact-active router-link-active">简体中文</a></li></ul></div></div> <a href="https://github.com/apache/iotdb.git" target="_blank" rel="noopener noreferrer" class="repo-link">
     gitHub
     <span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></nav>  <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading"><span>IoTDB用户手册 (In progress)</span> <!----></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>IoTDB简介</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>快速上手</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>数据模式与概念</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>SQL命令行终端(CLI)</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>权限管理</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading open"><span>IoTDB-SQL 语言</span> <span class="arrow down"></span></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/zh/UserGuide/Master/IoTDB-SQL-Language/DDL-Data-Definition-Language.html" class="sidebar-link">数据定义语言（DDL）</a></li><li><a href="/zh/UserGuide/Master/IoTDB-SQL-Language/DML-Data-Manipulation-Language.html" aria-current="page" class="active sidebar-link">数据操作语言（DML）</a></li><li><a href="/zh/UserGuide/Master/IoTDB-SQL-Language/Maintenance-Command.html" class="sidebar-link">运维命令</a></li></ul></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>应用编程接口</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>用户定义函数(UDF)</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>通信服务协议</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>系统工具</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>端云协同</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>系统集成</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>集群搭建</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>常见问题</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>附录</span> <span class="arrow right"></span></p> <!----></section></li></ul> </aside> <main class="page"> <div class="content content__default"><h2 id="数据操作语言-dml"><a href="#数据操作语言-dml" class="header-anchor">#</a> 数据操作语言（DML）</h2> <h3 id="数据写入"><a href="#数据写入" class="header-anchor">#</a> 数据写入</h3> <p>IoTDB为用户提供多种插入实时数据的方式，例如在<a href="/zh/UserGuide/Master/CLI/Command-Line-Interface.html">Cli/Shell工具</a>中直接输入插入数据的INSERT语句，或使用Java API（标准<a href="/zh/UserGuide/Master/API/Programming-JDBC.html">Java JDBC</a>接口）单条或批量执行插入数据的INSERT语句。</p> <p>本节主要为您介绍实时数据接入的INSERT语句在场景中的实际使用示例，有关INSERT SQL语句的详细语法请参见本文<a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">INSERT语句</a>节。</p> <h4 id="使用insert语句"><a href="#使用insert语句" class="header-anchor">#</a> 使用INSERT语句</h4> <p>使用INSERT语句可以向指定的已经创建的一条或多条时间序列中插入数据。对于每一条数据，均由一个时间戳类型的时间戳和一个数值或布尔值、字符串类型的传感器采集值组成。</p> <p>在本节的场景实例下，以其中的两个时间序列<code>root.ln.wf02.wt02.status</code>和<code>root.ln.wf02.wt02.hardware</code>为例 ，它们的数据类型分别为BOOLEAN和TEXT。</p> <p>单列数据插入示例代码如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB &gt; insert into root.ln.wf02.wt02(timestamp,status) values(1,true)
 IoTDB &gt; insert into root.ln.wf02.wt02(timestamp,hardware) values(1, &quot;v1&quot;)
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>以上示例代码将长整型的timestamp以及值为true的数据插入到时间序列<code>root.ln.wf02.wt02.status</code>中和将长整型的timestamp以及值为”v1”的数据插入到时间序列<code>root.ln.wf02.wt02.hardware</code>中。执行成功后会返回执行时间，代表数据插入已完成。</p> <blockquote><p>注意：在IoTDB中，TEXT类型的数据单双引号都可以来表示,上面的插入语句是用的是双引号表示TEXT类型数据，下面的示例将使用单引号表示TEXT类型数据。</p></blockquote> <p>INSERT语句还可以支持在同一个时间点下多列数据的插入，同时向2时间点插入上述两个时间序列的值，多列数据插入示例代码如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB &gt; insert into root.ln.wf02.wt02(timestamp, status, hardware) VALUES (2, false, 'v2')
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>插入数据后我们可以使用SELECT语句简单查询已插入的数据。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB &gt; select * from root.ln.wf02 where time &lt; 3
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果如图所示。由查询结果可以看出，单列、多列数据的插入操作正确执行。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------------------+------------------------+
 |                         Time|root.ln.wf02.wt02.hardware|root.ln.wf02.wt02.status|
 +-----------------------------+--------------------------+------------------------+
 |1970-01-01T08:00:00.001+08:00|                        v1|                    true|
 |1970-01-01T08:00:00.002+08:00|                        v2|                   false|
 +-----------------------------+--------------------------+------------------------+
 Total line number = 2
 It costs 0.170s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="数据查询"><a href="#数据查询" class="header-anchor">#</a> 数据查询</h3> <h4 id="时间条件过滤查询"><a href="#时间条件过滤查询" class="header-anchor">#</a> 时间条件过滤查询</h4> <p>本节主要介绍时间切片查询的相关示例，主要使用的是<a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">IoTDB SELECT语句</a>。同时，您也可以使用<a href="/zh/UserGuide/Master/API/Programming-JDBC.html">Java JDBC</a>标准接口来执行相关的查询语句。</p> <ul><li>根据一个时间区间选择一列数据</li></ul> <p>SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select temperature from root.ln.wf01.wt01 where time &lt; 2017-11-01T00:08:00.000
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>其含义为：</p> <p>被选择的设备为ln集团wf01子站wt01设备；被选择的时间序列为温度传感器（temperature）；该语句要求选择出该设备在“2017-11-01T00:08:00.000”（此处可以使用多种时间格式，详情可参看<a href="/zh/UserGuide/Master/Data-Concept/Data-Model-and-Terminology.html">2.1节</a>）时间点以前的所有温度传感器的值。</p> <p>该SQL语句的执行结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.temperature|
 +-----------------------------+-----------------------------+
 |2017-11-01T00:00:00.000+08:00|                        25.96|
 |2017-11-01T00:01:00.000+08:00|                        24.36|
 |2017-11-01T00:02:00.000+08:00|                        20.09|
 |2017-11-01T00:03:00.000+08:00|                        20.18|
 |2017-11-01T00:04:00.000+08:00|                        21.13|
 |2017-11-01T00:05:00.000+08:00|                        22.72|
 |2017-11-01T00:06:00.000+08:00|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                        21.45|
 +-----------------------------+-----------------------------+
 Total line number = 8
 It costs 0.026s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><ul><li>根据一个时间区间选择多列数据</li></ul> <p>SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status, temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>其含义为：</p> <p>被选择的设备为ln集团wf01子站wt01设备；被选择的时间序列为供电状态（status）和温度传感器（temperature）；该语句要求选择出“2017-11-01T00:05:00.000”至“2017-11-01T00:12:00.000”之间的所选时间序列的值。</p> <p>该SQL语句的执行结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 |2017-11-01T00:08:00.000+08:00|                   false|                        22.58|
 |2017-11-01T00:09:00.000+08:00|                   false|                        20.98|
 |2017-11-01T00:10:00.000+08:00|                    true|                        25.52|
 |2017-11-01T00:11:00.000+08:00|                   false|                        22.91|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 6
 It costs 0.018s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><ul><li>按照多个时间区间选择同一设备的多列数据</li></ul> <p>IoTDB支持在一次查询中指定多个时间区间条件，用户可以根据需求随意组合时间区间条件。例如，</p> <p>SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where (time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000) or (time &gt;= 2017-11-01T16:35:00.000 and time &lt;= 2017-11-01T16:37:00.000);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>其含义为：</p> <p>被选择的设备为ln集团wf01子站wt01设备；被选择的时间序列为“供电状态（status）”和“温度传感器（temperature）”；该语句指定了两个不同的时间区间，分别为“2017-11-01T00:05:00.000至2017-11-01T00:12:00.000”和“2017-11-01T16:35:00.000至2017-11-01T16:37:00.000”；该语句要求选择出满足任一时间区间的被选时间序列的值。</p> <p>该SQL语句的执行结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 |2017-11-01T00:08:00.000+08:00|                   false|                        22.58|
 |2017-11-01T00:09:00.000+08:00|                   false|                        20.98|
 |2017-11-01T00:10:00.000+08:00|                    true|                        25.52|
 |2017-11-01T00:11:00.000+08:00|                   false|                        22.91|
 |2017-11-01T16:35:00.000+08:00|                    true|                        23.44|
 |2017-11-01T16:36:00.000+08:00|                   false|                        21.98|
 |2017-11-01T16:37:00.000+08:00|                   false|                        21.93|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 9
 It costs 0.018s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><ul><li>按照多个时间区间选择不同设备的多列数据</li></ul> <p>该系统支持在一次查询中选择任意列的数据，也就是说，被选择的列可以来源于不同的设备。例如，SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select wf01.wt01.status,wf02.wt02.hardware from root.ln where (time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000) or (time &gt;= 2017-11-01T16:35:00.000 and time &lt;= 2017-11-01T16:37:00.000);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>其含义为：</p> <p>被选择的时间序列为“ln集团wf01子站wt01设备的供电状态”以及“ln集团wf02子站wt02设备的硬件版本”；该语句指定了两个时间区间，分别为“2017-11-01T00:05:00.000至2017-11-01T00:12:00.000”和“2017-11-01T16:35:00.000至2017-11-01T16:37:00.000”；该语句要求选择出满足任意时间区间的被选时间序列的值。</p> <p>该SQL语句的执行结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+--------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf02.wt02.hardware|
 +-----------------------------+------------------------+--------------------------+
 |2017-11-01T00:06:00.000+08:00|                   false|                        v1|
 |2017-11-01T00:07:00.000+08:00|                   false|                        v1|
 |2017-11-01T00:08:00.000+08:00|                   false|                        v1|
 |2017-11-01T00:09:00.000+08:00|                   false|                        v1|
 |2017-11-01T00:10:00.000+08:00|                    true|                        v2|
 |2017-11-01T00:11:00.000+08:00|                   false|                        v1|
 |2017-11-01T16:35:00.000+08:00|                    true|                        v2|
 |2017-11-01T16:36:00.000+08:00|                   false|                        v1|
 |2017-11-01T16:37:00.000+08:00|                   false|                        v1|
 +-----------------------------+------------------------+--------------------------+
 Total line number = 9
 It costs 0.014s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><h4 id="其他结果对齐方式"><a href="#其他结果对齐方式" class="header-anchor">#</a> 其他结果对齐方式</h4> <ul><li>根据时间降序返回
 IoTDB 在 0.11 版本开始支持 'order by time' 语句, 用于对结果按照时间进行降序展示。例如，SQL语句为：</li></ul> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> <span class="token operator">*</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>ln <span class="token keyword">where</span> <span class="token keyword">time</span> <span class="token operator">&gt;</span> <span class="token number">1</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> <span class="token keyword">limit</span> <span class="token number">10</span><span class="token punctuation">;</span>
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>语句执行的结果为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
 |                         Time|root.ln.wf02.wt02.hardware|root.ln.wf02.wt02.status|root.ln.wf01.wt01.temperature|root.ln.wf01.wt01.status|
 +-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
 |2017-11-07T23:59:00.000+08:00|                        v1|                   false|                        21.07|                   false|
 |2017-11-07T23:58:00.000+08:00|                        v1|                   false|                        22.93|                   false|
 |2017-11-07T23:57:00.000+08:00|                        v2|                    true|                        24.39|                    true|
 |2017-11-07T23:56:00.000+08:00|                        v2|                    true|                        24.44|                    true|
 |2017-11-07T23:55:00.000+08:00|                        v2|                    true|                         25.9|                    true|
 |2017-11-07T23:54:00.000+08:00|                        v1|                   false|                        22.52|                   false|
 |2017-11-07T23:53:00.000+08:00|                        v2|                    true|                        24.58|                    true|
 |2017-11-07T23:52:00.000+08:00|                        v1|                   false|                        20.18|                   false|
 |2017-11-07T23:51:00.000+08:00|                        v1|                   false|                        22.24|                   false|
 |2017-11-07T23:50:00.000+08:00|                        v2|                    true|                         23.7|                    true|
 +-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
 Total line number = 10
 It costs 0.016s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br></div></div><p>更多语法请参照 <a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">SQL REFERENCE</a>.</p> <ul><li>IoTDB支持另外两种结果返回形式: 按设备时间对齐 'align by device' 和 时序不对齐 'disable align'.</li></ul> <p>'align by device' 对齐方式下，设备ID会单独作为一列出现。在 select 子句中写了多少列，最终结果就会有该列数+2 （时间列和设备名字列）。SQL形如:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.ln.* where time &lt;= 2017-11-01T00:01:00 align by device
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------+-----------+------+--------+
 |                         Time|           Device|temperature|status|hardware|
 +-----------------------------+-----------------+-----------+------+--------+
 |2017-11-01T00:00:00.000+08:00|root.ln.wf01.wt01|      25.96|  true|    null|
 |2017-11-01T00:01:00.000+08:00|root.ln.wf01.wt01|      24.36|  true|    null|
 |1970-01-01T08:00:00.001+08:00|root.ln.wf02.wt02|       null|  true|      v1|
 |1970-01-01T08:00:00.002+08:00|root.ln.wf02.wt02|       null| false|      v2|
 |2017-11-01T00:00:00.000+08:00|root.ln.wf02.wt02|       null|  true|      v2|
 |2017-11-01T00:01:00.000+08:00|root.ln.wf02.wt02|       null|  true|      v2|
 +-----------------------------+-----------------+-----------+------+--------+
 Total line number = 6
 It costs 0.012s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><p>'disable align' 意味着每条时序就有 2 列存在。Disable Align只能用于查询语句句尾，不能用于聚合查询、Fill语句、Group by或Group by device语句，但可用于Limit语句。结果显示若无数据显示为空白。</p> <p>SQL形如:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.ln.* where time &lt;= 2017-11-01T00:01:00 disable align
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------------------+-----------------------------+------------------------+-----------------------------+-----------------------------+-----------------------------+------------------------+
 |                         Time|root.ln.wf02.wt02.hardware|                         Time|root.ln.wf02.wt02.status|                         Time|root.ln.wf01.wt01.temperature|                         Time|root.ln.wf01.wt01.status|
 +-----------------------------+--------------------------+-----------------------------+------------------------+-----------------------------+-----------------------------+-----------------------------+------------------------+
 |1970-01-01T08:00:00.001+08:00|                        v1|1970-01-01T08:00:00.001+08:00|                    true|2017-11-01T00:00:00.000+08:00|                        25.96|2017-11-01T00:00:00.000+08:00|                    true|
 |1970-01-01T08:00:00.002+08:00|                        v2|1970-01-01T08:00:00.002+08:00|                   false|2017-11-01T00:01:00.000+08:00|                        24.36|2017-11-01T00:01:00.000+08:00|                    true|
 |2017-11-01T00:00:00.000+08:00|                        v2|2017-11-01T00:00:00.000+08:00|                    true|                         null|                         null|                         null|                    null|
 |2017-11-01T00:01:00.000+08:00|                        v2|2017-11-01T00:01:00.000+08:00|                    true|                         null|                         null|                         null|                    null|
 +-----------------------------+--------------------------+-----------------------------+------------------------+-----------------------------+-----------------------------+-----------------------------+------------------------+
 Total line number = 4
 It costs 0.018s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br></div></div><p>更多语法请参照<a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">SQL REFERENCE</a>。</p> <h4 id="聚合函数"><a href="#聚合函数" class="header-anchor">#</a> 聚合函数</h4> <p>本章节主要介绍聚合查询的相关示例，
 主要使用的是IoTDB SELECT语句的聚合查询函数。</p> <ul><li>统计总点数</li></ul> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-------------------------------+
 |count(root.ln.wf01.wt01.status)|
 +-------------------------------+
 |                          10080|
 +-------------------------------+
 Total line number = 1
 It costs 0.016s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><h4 id="时间区间分组聚合"><a href="#时间区间分组聚合" class="header-anchor">#</a> 时间区间分组聚合</h4> <p>本章节主要介绍时间区间分组聚合查询的相关示例，
 主要使用的是IoTDB SELECT语句的<a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">GROUP BY子句</a>，
 该子句是IoTDB中用于根据用户给定划分条件对结果集进行划分，并对已划分的结果集进行聚合计算的语句。
 IoTDB支持根据时间间隔和自定义的滑动步长（默认值与时间间隔相同，自定义的值必须大于等于时间间隔）对结果集进行划分，默认结果按照时间升序排列。
 同时，您也可以使用Java JDBC标准接口来执行相关的查询语句。</p> <p>GROUP BY语句为用户提供三类指定参数：</p> <ul><li>参数1：时间轴显示时间窗参数</li> <li>参数2：划分时间轴的时间间隔参数（必须为正数）</li> <li>参数3：滑动步长（可选参数，默认值与时间间隔相同，自定义的值必须大于等于时间间隔）</li></ul> <p>三类参数的实际含义已经在下图中指出，这三类参数里，第三个参数是可选的。
 接下来，我们将给出三种典型的降频聚合查询的例子：
 滑动步长未指定，
 指定滑动步长，
 带值过滤条件。</p> <img src="https://user-images.githubusercontent.com/16079446/69109512-f808bc80-0ab2-11ea-9e4d-b2b2f58fb474.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"> <ul><li>未指定滑动步长的降频聚合查询</li></ul> <p>对应的SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status), max_value(temperature) from root.ln.wf01.wt01 group by ([2017-11-01T00:00:00, 2017-11-07T23:00:00),1d);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这条查询的含义是:</p> <p>由于用户没有指定滑动步长，滑动步长将会被默认设置为跟时间间隔参数相同，也就是<code>1d</code>。</p> <p>上面这个例子的第一个参数是显示窗口参数，决定了最终的显示范围是[2017-11-01T00:00:00, 2017-11-07T23:00:00)。</p> <p>上面这个例子的第二个参数是划分时间轴的时间间隔参数，将<code>1d</code>当作划分间隔，显示窗口参数的起始时间当作分割原点，时间轴即被划分为连续的时间间隔：[0,1d), [1d, 2d), [2d, 3d)等等。</p> <p>然后系统将会用WHERE子句中的时间和值过滤条件以及GROUP BY语句中的第一个参数作为数据的联合过滤条件，获得满足所有过滤条件的数据（在这个例子里是在[2017-11-01T00:00:00, 2017-11-07 T23:00:00)这个时间范围的数据），并把这些数据映射到之前分割好的时间轴中（这个例子里是从2017-11-01T00:00:00到2017-11-07T23:00:00:00的每一天）</p> <p>每个时间间隔窗口内都有数据，SQL执行后的结果集如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+----------------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|max_value(root.ln.wf01.wt01.temperature)|
 +-----------------------------+-------------------------------+----------------------------------------+
 |2017-11-01T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-02T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-03T00:00:00.000+08:00|                           1440|                                   25.99|
 |2017-11-04T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-05T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-06T00:00:00.000+08:00|                           1440|                                   25.99|
 |2017-11-07T00:00:00.000+08:00|                           1380|                                    26.0|
 +-----------------------------+-------------------------------+----------------------------------------+
 Total line number = 7
 It costs 0.024s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><ul><li>指定滑动步长的时间区间分组聚合查询</li></ul> <p>对应的SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status), max_value(temperature) from root.ln.wf01.wt01 group by ([2017-11-01 00:00:00, 2017-11-07 23:00:00), 3h, 1d);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这条查询的含义是:</p> <p>由于用户指定了滑动步长为<code>1d</code>，GROUP BY语句执行时将会每次把时间间隔往后移动一天的步长，而不是默认的3小时。</p> <p>也就意味着，我们想要取从2017-11-01到2017-11-07每一天的凌晨0点到凌晨3点的数据。</p> <p>上面这个例子的第一个参数是显示窗口参数，决定了最终的显示范围是[2017-11-01T00:00:00, 2017-11-07T23:00:00)。</p> <p>上面这个例子的第二个参数是划分时间轴的时间间隔参数，将<code>3h</code>当作划分间隔，显示窗口参数的起始时间当作分割原点，时间轴即被划分为连续的时间间隔：[2017-11-01T00:00:00, 2017-11-01T03:00:00), [2017-11-02T00:00:00, 2017-11-02T03:00:00), [2017-11-03T00:00:00, 2017-11-03T03:00:00)等等。</p> <p>上面这个例子的第三个参数是每次时间间隔的滑动步长。</p> <p>然后系统将会用WHERE子句中的时间和值过滤条件以及GROUP BY语句中的第一个参数作为数据的联合过滤条件，获得满足所有过滤条件的数据（在这个例子里是在[2017-11-01T00:00:00, 2017-11-07 T23:00:00)这个时间范围的数据），并把这些数据映射到之前分割好的时间轴中（这个例子里是从2017-11-01T00:00:00到2017-11-07T23:00:00:00的每一天的凌晨0点到凌晨3点）</p> <p>每个时间间隔窗口内都有数据，SQL执行后的结果集如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+----------------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|max_value(root.ln.wf01.wt01.temperature)|
 +-----------------------------+-------------------------------+----------------------------------------+
 |2017-11-01T00:00:00.000+08:00|                            180|                                   25.98|
 |2017-11-02T00:00:00.000+08:00|                            180|                                   25.98|
 |2017-11-03T00:00:00.000+08:00|                            180|                                   25.96|
 |2017-11-04T00:00:00.000+08:00|                            180|                                   25.96|
 |2017-11-05T00:00:00.000+08:00|                            180|                                    26.0|
 |2017-11-06T00:00:00.000+08:00|                            180|                                   25.85|
 |2017-11-07T00:00:00.000+08:00|                            180|                                   25.99|
 +-----------------------------+-------------------------------+----------------------------------------+
 Total line number = 7
 It costs 0.006s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><ul><li>按照自然月份的时间区间分组聚合查询</li></ul> <p>对应的SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 where time &gt; 2017-11-01T01:00:00 group by([2017-11-01T00:00:00, 2019-11-07T23:00:00), 1mo, 2mo);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这条查询的含义是:</p> <p>由于用户指定了滑动步长为<code>2mo</code>，GROUP BY语句执行时将会每次把时间间隔往后移动2个自然月的步长，而不是默认的1个自然月。</p> <p>也就意味着，我们想要取从2017-11-01到2019-11-07每2个自然月的第一个月的数据。</p> <p>上面这个例子的第一个参数是显示窗口参数，决定了最终的显示范围是[2017-11-01T00:00:00, 2019-11-07T23:00:00)。</p> <p>起始时间为2017-11-01T00:00:00，滑动步长将会以起始时间作为标准按月递增，取当月的1号作为时间间隔的起始时间。</p> <p>上面这个例子的第二个参数是划分时间轴的时间间隔参数，将<code>1mo</code>当作划分间隔，显示窗口参数的起始时间当作分割原点，时间轴即被划分为连续的时间间隔：[2017-11-01T00:00:00, 2017-12-01T00:00:00), [2018-02-01T00:00:00, 2018-03-01T00:00:00), [2018-05-03T00:00:00, 2018-06-01T00:00:00)等等。</p> <p>上面这个例子的第三个参数是每次时间间隔的滑动步长。</p> <p>然后系统将会用WHERE子句中的时间和值过滤条件以及GROUP BY语句中的第一个参数作为数据的联合过滤条件，获得满足所有过滤条件的数据（在这个例子里是在[2017-11-01T00:00:00, 2019-11-07T23:00:00)这个时间范围的数据），并把这些数据映射到之前分割好的时间轴中（这个例子里是从2017-11-01T00:00:00到2019-11-07T23:00:00:00的每两个自然月的第一个月）</p> <p>每个时间间隔窗口内都有数据，SQL执行后的结果集如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|
 +-----------------------------+-------------------------------+
 |2017-11-01T00:00:00.000+08:00|                            259|
 |2018-01-01T00:00:00.000+08:00|                            250|
 |2018-03-01T00:00:00.000+08:00|                            259|
 |2018-05-01T00:00:00.000+08:00|                            251|
 |2018-07-01T00:00:00.000+08:00|                            242|
 |2018-09-01T00:00:00.000+08:00|                            225|
 |2018-11-01T00:00:00.000+08:00|                            216|
 |2019-01-01T00:00:00.000+08:00|                            207|
 |2019-03-01T00:00:00.000+08:00|                            216|
 |2019-05-01T00:00:00.000+08:00|                            207|
 |2019-07-01T00:00:00.000+08:00|                            199|
 |2019-09-01T00:00:00.000+08:00|                            181|
 |2019-11-01T00:00:00.000+08:00|                             60|
 +-----------------------------+-------------------------------+
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br></div></div><p>对应的SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by([2017-10-31T00:00:00, 2019-11-07T23:00:00), 1mo, 2mo);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这条查询的含义是:</p> <p>由于用户指定了滑动步长为<code>2mo</code>，GROUP BY语句执行时将会每次把时间间隔往后移动2个自然月的步长，而不是默认的1个自然月。</p> <p>也就意味着，我们想要取从2017-10-31到2019-11-07每2个自然月的第一个月的数据。</p> <p>与上述示例不同的是起始时间为2017-10-31T00:00:00，滑动步长将会以起始时间作为标准按月递增，取当月的31号（即最后一天）作为时间间隔的起始时间。若起始时间设置为30号，滑动步长会将时间间隔的起始时间设置为当月30号，若不存在则为最后一天。</p> <p>上面这个例子的第一个参数是显示窗口参数，决定了最终的显示范围是[2017-10-31T00:00:00, 2019-11-07T23:00:00)。</p> <p>上面这个例子的第二个参数是划分时间轴的时间间隔参数，将<code>1mo</code>当作划分间隔，显示窗口参数的起始时间当作分割原点，时间轴即被划分为连续的时间间隔：[2017-10-31T00:00:00, 2017-11-31T00:00:00), [2018-02-31T00:00:00, 2018-03-31T00:00:00), [2018-05-31T00:00:00, 2018-06-31T00:00:00)等等。</p> <p>上面这个例子的第三个参数是每次时间间隔的滑动步长。</p> <p>然后系统将会用WHERE子句中的时间和值过滤条件以及GROUP BY语句中的第一个参数作为数据的联合过滤条件，获得满足所有过滤条件的数据（在这个例子里是在[2017-10-31T00:00:00, 2019-11-07T23:00:00)这个时间范围的数据），并把这些数据映射到之前分割好的时间轴中（这个例子里是从2017-10-31T00:00:00到2019-11-07T23:00:00:00的每两个自然月的第一个月）</p> <p>每个时间间隔窗口内都有数据，SQL执行后的结果集如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|
 +-----------------------------+-------------------------------+
 |2017-10-31T00:00:00.000+08:00|                            251|
 |2017-12-31T00:00:00.000+08:00|                            250|
 |2018-02-28T00:00:00.000+08:00|                            259|
 |2018-04-30T00:00:00.000+08:00|                            250|
 |2018-06-30T00:00:00.000+08:00|                            242|
 |2018-08-31T00:00:00.000+08:00|                            225|
 |2018-10-31T00:00:00.000+08:00|                            216|
 |2018-12-31T00:00:00.000+08:00|                            208|
 |2019-02-28T00:00:00.000+08:00|                            216|
 |2019-04-30T00:00:00.000+08:00|                            208|
 |2019-06-30T00:00:00.000+08:00|                            199|
 |2019-08-31T00:00:00.000+08:00|                            181|
 |2019-10-31T00:00:00.000+08:00|                             69|
 +-----------------------------+-------------------------------+
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br></div></div><ul><li>左开右闭区间</li></ul> <p>每个区间的结果时间戳为区间右端点，对应的SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by ((2017-11-01T00:00:00, 2017-11-07T23:00:00],1d);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这条查询语句的时间区间是左开右闭的，结果中不会包含时间点2017-11-01的数据，但是会包含时间点2017-11-07的数据。</p> <p>SQL执行后的结果集如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|
 +-----------------------------+-------------------------------+
 |2017-11-02T00:00:00.000+08:00|                           1440|
 |2017-11-03T00:00:00.000+08:00|                           1440|
 |2017-11-04T00:00:00.000+08:00|                           1440|
 |2017-11-05T00:00:00.000+08:00|                           1440|
 |2017-11-06T00:00:00.000+08:00|                           1440|
 |2017-11-07T00:00:00.000+08:00|                           1440|
 |2017-11-07T23:00:00.000+08:00|                           1380|
 +-----------------------------+-------------------------------+
 Total line number = 7
 It costs 0.004s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><h4 id="路径层级分组聚合"><a href="#路径层级分组聚合" class="header-anchor">#</a> 路径层级分组聚合</h4> <p>在时间序列层级结构中，分层聚合查询用于对某一层级进行聚合查询。
 这里使用LEVEL来统计指定层级下的聚合范围，该语句约定root为第0层序列，若统计&quot;root.ln&quot;下所有序列则需指定level为1。</p> <p>例如：在&quot;root.ln.wf01&quot;下存在多个子序列：wt01，wt02，wt03等均有名为status的序列，
 如果需要统计这些子序列的status包含的点个数，使用以下查询:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.* group by level=2
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>运行结果为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+----------------------------+
 |count(root.ln.wf01.*.status)|
 +----------------------------+
 |                       10080|
 +----------------------------+
 Total line number = 1
 It costs 0.003s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>假设此时添加两条序列，&quot;root.ln.wf01.wt01.temperature&quot; and &quot;root.ln.wf02.wt01.temperature&quot;。
 需要同时查询&quot;root.ln.*.*.temperature&quot;在第二层级的count聚合结果和sum聚合结果，可以使用下列查询语句：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(temperature), sum(temperature) from root.ln.*.* group by level=2
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>运行结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+---------------------------------+---------------------------------+-------------------------------+-------------------------------+
 |count(root.ln.wf02.*.temperature)|count(root.ln.wf01.*.temperature)|sum(root.ln.wf02.*.temperature)|sum(root.ln.wf01.*.temperature)|
 +---------------------------------+---------------------------------+-------------------------------+-------------------------------+
 |                                8|                                4|                          228.0|              91.83000183105469|
 +---------------------------------+---------------------------------+-------------------------------+-------------------------------+
 Total line number = 1
 It costs 0.013s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>若统计&quot;root.ln.*.*&quot;下第一层级的count聚合结果和sum聚合结果，则设置level=1即可:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(temperature), sum(temperature) from root.ln.*.* group by level=1
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>运行结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+------------------------------+----------------------------+
 |count(root.ln.*.*.temperature)|sum(root.ln.*.*.temperature)|
 +------------------------------+----------------------------+
 |                            12|           319.8300018310547|
 +------------------------------+----------------------------+
 Total line number = 1
 It costs 0.013s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>分层聚合查询也可被用于其他聚合函数，当前所支持的聚合函数为：count, sum, avg, last_value, first_value, min_time, max_time, min_value, max_value</p> <p>对于sum, avg, min_value, max_value四种聚合函数，需保证所有聚合的时间序列数据类型相同。其他聚合函数没有此限制。</p> <h4 id="时间区间和路径层级分组聚合查询"><a href="#时间区间和路径层级分组聚合查询" class="header-anchor">#</a> 时间区间和路径层级分组聚合查询</h4> <p>除此之外，还可以通过定义LEVEL来统计指定层级下的数据点个数。</p> <p>例如：</p> <p>统计降采样后的数据点个数</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by ((2017-11-01T00:00:00, 2017-11-07T23:00:00],1d), level=1;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------+
 |                         Time|COUNT(root.ln.*.*.status)|
 +-----------------------------+-------------------------+
 |2017-11-02T00:00:00.000+08:00|                     1440|
 |2017-11-03T00:00:00.000+08:00|                     1440|
 |2017-11-04T00:00:00.000+08:00|                     1440|
 |2017-11-05T00:00:00.000+08:00|                     1440|
 |2017-11-06T00:00:00.000+08:00|                     1440|
 |2017-11-07T00:00:00.000+08:00|                     1440|
 |2017-11-07T23:00:00.000+08:00|                     1380|
 +-----------------------------+-------------------------+
 Total line number = 7
 It costs 0.006s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><p>加上滑动Step的降采样后的结果也可以汇总</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by ([0,20),2ms,3ms), level=1;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------+
 |                         Time|COUNT(root.ln.*.*.status)|
 +-----------------------------+-------------------------+
 |2017-11-01T00:00:00.000+08:00|                      180|
 |2017-11-02T00:00:00.000+08:00|                      180|
 |2017-11-03T00:00:00.000+08:00|                      180|
 |2017-11-04T00:00:00.000+08:00|                      180|
 |2017-11-05T00:00:00.000+08:00|                      180|
 |2017-11-06T00:00:00.000+08:00|                      180|
 |2017-11-07T00:00:00.000+08:00|                      180|
 +-----------------------------+-------------------------+
 Total line number = 7
 It costs 0.004s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><h4 id="最新点查询"><a href="#最新点查询" class="header-anchor">#</a> 最新点查询</h4> <p>SQL语法：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select last &lt;Path&gt; [COMMA &lt;Path&gt;]* from &lt; PrefixPath &gt; [COMMA &lt; PrefixPath &gt;]* &lt;WhereClause&gt;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>其含义是：查询时间序列prefixPath.path中最近时间戳的数据</p> <p>&lt;WhereClause&gt;中当前只支持含有'&gt;'或'&gt;='的时间过滤条件，任何其他过滤条件都将会返回异常。</p> <p>结果集为三列的结构</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+----+----------+-----+
 |Time|timeseries|value|
 +----+----------+-----+
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><p>示例 1：查询 root.ln.wf01.wt01.status 的最新数据点</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB&gt; select last status from root.ln.wf01.wt01
 +-----------------------------+------------------------+-----+
 |                         Time|              timeseries|value|
 +-----------------------------+------------------------+-----+
 |2017-11-07T23:59:00.000+08:00|root.ln.wf01.wt01.status|false|
 +-----------------------------+------------------------+-----+
 Total line number = 1
 It costs 0.000s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p>示例 2：查询 root.ln.wf01.wt01 下 status，temperature 时间戳大于等于2017-11-07T23:50:00的最新数据点。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB&gt; select last status, temperature from root.ln.wf01.wt01 where time &gt;= 2017-11-07T23:50:00
 +-----------------------------+-----------------------------+---------+
 |                         Time|                   timeseries|    value|
 +-----------------------------+-----------------------------+---------+
 |2017-11-07T23:59:00.000+08:00|     root.ln.wf01.wt01.status|    false|
 |2017-11-07T23:59:00.000+08:00|root.ln.wf01.wt01.temperature|21.067368|
 +-----------------------------+-----------------------------+---------+
 Total line number = 2
 It costs 0.002s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><h4 id="空值填充"><a href="#空值填充" class="header-anchor">#</a> 空值填充</h4> <p>在IoTDB的实际使用中，当进行时间序列的查询操作时，可能会出现在某些时间点值为null的情况，这会妨碍用户进行进一步的分析。 为了更好地反映数据更改的程度，用户希望可以自动填充缺失值。 因此，IoTDB系统引入了自动填充功能。</p> <p>自动填充功能是指对单列或多列执行时间序列查询时，根据用户指定的方法和有效时间范围填充空值。 如果查询点的值不为null，则填充功能将不起作用。</p> <blockquote><p>注意：在当前版本中，IoTDB为用户提供两种方法：Previous 和Linear。 Previous 方法用前一个值填充空白。 Linear方法通过线性拟合来填充空白。 并且填充功能只能在执行时间点查询时使用。</p></blockquote> <ul><li>填充功能</li></ul> <ul><li>Previous功能</li></ul> <p>当查询的时间戳值为空时，将使用前一个时间戳的值来填充空白。 形式化的先前方法如下（有关详细语法，请参见第7.1.3.6节）：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select &lt;path&gt; from &lt;prefixPath&gt; where time = &lt;T&gt; fill(&lt;data_type&gt;[previous, &lt;before_range&gt;], …)
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>表3-4给出了所有参数的详细说明。</p> <center>**表3-4previous填充参数列表**
 <table><thead><tr><th style="text-align:left;">参数名称（不区分大小写）</th> <th style="text-align:left;">解释</th></tr></thead> <tbody><tr><td style="text-align:left;">path, prefixPath</td> <td style="text-align:left;">查询路径； 必填项</td></tr> <tr><td style="text-align:left;">T</td> <td style="text-align:left;">查询时间戳（只能指定一个）； 必填项</td></tr> <tr><td style="text-align:left;">data_type</td> <td style="text-align:left;">填充方法使用的数据类型。 可选值是int32，int64，float，double，boolean，text; 可选字段</td></tr> <tr><td style="text-align:left;">before_range</td> <td style="text-align:left;">表示前一种方法的有效时间范围。 当[T-before \ _range，T]范围内的值存在时，前一种方法将起作用。 如果未指定before_range，则before_range会使用默认值default_fill_interval; -1表示无穷大； 可选字段</td></tr></tbody></table></center> <p>在这里，我们举一个使用先前方法填充空值的示例。 SQL语句如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select temperature from root.sgcc.wf03.wt01 where time = 2017-11-01T16:37:50.000 fill(float[previous, 1m])
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>由于时间根目录root.sgcc.wf03.wt01.temperature在2017-11-01T16：37：50.000为空，因此系统使用以前的时间戳2017-11-01T16：37：00.000（且时间戳位于[2017-11-01T16:36:50.000, 2017-11-01T16:37:50.000]范围）进行填充和显示。</p> <p>在<a href="https://github.com/thulab/iotdb/files/4438687/OtherMaterial-Sample.Data.txt" target="_blank" rel="noopener noreferrer">样例数据中<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a>, 该语句的执行结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+
 |                         Time|root.sgcc.wf03.wt01.temperature|
 +-----------------------------+-------------------------------+
 |2017-11-01T16:37:50.000+08:00|                          21.93|
 +-----------------------------+-------------------------------+
 Total line number = 1
 It costs 0.016s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>值得注意的是，如果在指定的有效时间范围内没有值，系统将不会填充空值，如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB&gt; select temperature from root.sgcc.wf03.wt01 where time = 2017-11-01T16:37:50.000 fill(float[previous, 1s])
 +-----------------------------+-------------------------------+
 |                         Time|root.sgcc.wf03.wt01.temperature|
 +-----------------------------+-------------------------------+
 |2017-11-01T16:37:50.000+08:00|                           null|
 +-----------------------------+-------------------------------+
 Total line number = 1
 It costs 0.004s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><ul><li>Linear方法</li></ul> <p>当查询的时间戳值为空时，将使用前一个和下一个时间戳的值来填充空白。 形式化线性方法如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select &lt;path&gt; from &lt;prefixPath&gt; where time = &lt;T&gt; fill(&lt;data_type&gt;[linear, &lt;before_range&gt;, &lt;after_range&gt;]…)
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>表3-5中给出了所有参数的详细说明。</p> <center>**表3-5线性填充参数列表**
 <table><thead><tr><th style="text-align:left;">参数名称（不区分大小写）</th> <th style="text-align:left;">解释</th></tr></thead> <tbody><tr><td style="text-align:left;">path, prefixPath</td> <td style="text-align:left;">查询路径； 必填项</td></tr> <tr><td style="text-align:left;">T</td> <td style="text-align:left;">查询时间戳（只能指定一个）； 必填项</td></tr> <tr><td style="text-align:left;">data_type</td> <td style="text-align:left;">填充方法使用的数据类型。 可选值是int32，int64，float，double，boolean，text; 可选字段</td></tr> <tr><td style="text-align:left;">before_range, after_range</td> <td style="text-align:left;">表示线性方法的有效时间范围。 当[T-before_range，T + after_range]范围内的值存在时，前一种方法将起作用。 如果未明确指定before_range和after_range，则使用default_fill_interval。 -1表示无穷大； 可选字段</td></tr></tbody></table></center> <p>需要注意的是一旦时间序列在查询时间戳T时刻存在有效值，线性填充就回使用这个值作为结果返回。
 除此之外，如果在[T-before_range，T]或[T, T + after_range]两个范围中任意一个范围内不存在有效填充值，则线性填充返回null值。</p> <p>在这里，我们举一个使用线性方法填充空值的示例。 SQL语句如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select temperature from root.sgcc.wf03.wt01 where time = 2017-11-01T16:37:50.000 fill(float [linear, 1m, 1m])
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>由于时间根目录root.sgcc.wf03.wt01.temperature在2017-11-01T16：37：50.000为空，因此系统使用以前的时间戳2017-11-01T16：37：00.000（且时间戳位于[2017- 11-01T16：36：50.000，2017-11-01T16：37：50.000]时间范围）及其值21.927326，下一个时间戳记2017-11-01T16：38：00.000（且时间戳记位于[2017-11-11] 01T16：37：50.000、2017-11-01T16：38：50.000]时间范围）及其值25.311783以执行线性拟合计算：</p> <p>21.927326 +（25.311783-21.927326）/ 60s * 50s = 24.747707</p> <p>在 <a href="https://github.com/thulab/iotdb/files/4438687/OtherMaterial-Sample.Data.txt" target="_blank" rel="noopener noreferrer">样例数据<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a>, 该语句的执行结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+
 |                         Time|root.sgcc.wf03.wt01.temperature|
 +-----------------------------+-------------------------------+
 |2017-11-01T16:37:50.000+08:00|                      24.746666|
 +-----------------------------+-------------------------------+
 Total line number = 1
 It costs 0.017s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>数据类型和填充方法之间的对应关系</p> <p>数据类型和支持的填充方法如表3-6所示。</p> <center>**表3-6数据类型和支持的填充方法**
 <table><thead><tr><th style="text-align:left;">数据类型</th> <th style="text-align:left;">支持的填充方法</th></tr></thead> <tbody><tr><td style="text-align:left;">boolean</td> <td style="text-align:left;">previous</td></tr> <tr><td style="text-align:left;">int32</td> <td style="text-align:left;">previous, linear</td></tr> <tr><td style="text-align:left;">int64</td> <td style="text-align:left;">previous, linear</td></tr> <tr><td style="text-align:left;">float</td> <td style="text-align:left;">previous, linear</td></tr> <tr><td style="text-align:left;">double</td> <td style="text-align:left;">previous, linear</td></tr> <tr><td style="text-align:left;">text</td> <td style="text-align:left;">previous</td></tr></tbody></table></center> <blockquote><p>注意：应在Fill语句中至少指定一种填充方法。</p></blockquote> <ul><li>时间区间分组聚合查询补空值</li></ul> <p>时间区间分组聚合出的各个时间段的结果，支持使用前值补空。</p> <p>不允许设置滑动步长，默认为聚合时间区间，实际为定长采样。现在只支持 last_value 聚合函数。</p> <p>目前不支持线性插值补空值。</p> <p>PREVIOUS 和 PREVIOUSUNTILLAST 的区别</p> <ul><li>PREVIOUS：只要空值前边有值，就会用其填充空值。</li> <li>PREVIOUSUNTILLAST：不会填充此序列最新点后的空值</li></ul> <p>首先我们检查一下root.ln.wf01.wt01.temperature在时间2017-11-07T23:50:00以后的值</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB&gt; SELECT temperature FROM root.ln.wf01.wt01 where time &gt;= 2017-11-07T23:50:00
 +-----------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.temperature|
 +-----------------------------+-----------------------------+
 |2017-11-07T23:50:00.000+08:00|                         23.7|
 |2017-11-07T23:51:00.000+08:00|                        22.24|
 |2017-11-07T23:52:00.000+08:00|                        20.18|
 |2017-11-07T23:53:00.000+08:00|                        24.58|
 |2017-11-07T23:54:00.000+08:00|                        22.52|
 |2017-11-07T23:55:00.000+08:00|                         25.9|
 |2017-11-07T23:56:00.000+08:00|                        24.44|
 |2017-11-07T23:57:00.000+08:00|                        24.39|
 |2017-11-07T23:58:00.000+08:00|                        22.93|
 |2017-11-07T23:59:00.000+08:00|                        21.07|
 +-----------------------------+-----------------------------+
 Total line number = 10
 It costs 0.002s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br></div></div><p>我们发现root.ln.wf01.wt01.temperature的最后时间和值是2017-11-07T23:59:00和21.07。</p> <p>SQL 示例:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>SELECT last_value(temperature) FROM root.ln.wf01.wt01 GROUP BY([2017-11-07T23:50:00, 2017-11-08T00:01:00),1m) FILL (float[PREVIOUSUNTILLAST]);
 SELECT last_value(temperature) FROM root.ln.wf01.wt01 GROUP BY([2017-11-07T23:50:00, 2017-11-08T00:01:00),1m) FILL (float[PREVIOUS]);
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------------------------------+
 |                         Time|last_value(root.ln.wf01.wt01.temperature)|
 +-----------------------------+-----------------------------------------+
 |2017-11-07T23:50:00.000+08:00|                                     23.7|
 |2017-11-07T23:51:00.000+08:00|                                    22.24|
 |2017-11-07T23:52:00.000+08:00|                                    20.18|
 |2017-11-07T23:53:00.000+08:00|                                    24.58|
 |2017-11-07T23:54:00.000+08:00|                                    22.52|
 |2017-11-07T23:55:00.000+08:00|                                     25.9|
 |2017-11-07T23:56:00.000+08:00|                                    24.44|
 |2017-11-07T23:57:00.000+08:00|                                    24.39|
 |2017-11-07T23:58:00.000+08:00|                                    22.93|
 |2017-11-07T23:59:00.000+08:00|                                    21.07|
 |2017-11-08T00:00:00.000+08:00|                                     null|
 +-----------------------------+-----------------------------------------+
 Total line number = 11
 It costs 0.005s

 +-----------------------------+-----------------------------------------+
 |                         Time|last_value(root.ln.wf01.wt01.temperature)|
 +-----------------------------+-----------------------------------------+
 |2017-11-07T23:50:00.000+08:00|                                     23.7|
 |2017-11-07T23:51:00.000+08:00|                                    22.24|
 |2017-11-07T23:52:00.000+08:00|                                    20.18|
 |2017-11-07T23:53:00.000+08:00|                                    24.58|
 |2017-11-07T23:54:00.000+08:00|                                    22.52|
 |2017-11-07T23:55:00.000+08:00|                                     25.9|
 |2017-11-07T23:56:00.000+08:00|                                    24.44|
 |2017-11-07T23:57:00.000+08:00|                                    24.39|
 |2017-11-07T23:58:00.000+08:00|                                    22.93|
 |2017-11-07T23:59:00.000+08:00|                                    21.07|
 |2017-11-08T00:00:00.000+08:00|                                    21.07|
 +-----------------------------+-----------------------------------------+
 Total line number = 11
 It costs 0.006s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br></div></div><p>解释:</p> <p>使用 PREVIOUSUNTILLAST 将不会填充2017-11-07T23:59:00以后的值。</p> <h4 id="limit-offset"><a href="#limit-offset" class="header-anchor">#</a> LIMIT &amp; OFFSET</h4> <p>IoTDB提供 <a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">LIMIT/SLIMIT</a> 子句和 <a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">OFFSET/SOFFSET</a> 子句，以使用户可以更好地控制查询结果。使用LIMIT和SLIMIT子句可让用户控制查询结果的行数和列数，
 并且使用OFFSET和SOFSET子句允许用户设置结果显示的起始位置。</p> <p>请注意，按组查询不支持LIMIT和OFFSET。</p> <p>本章主要介绍查询结果的行和列控制的相关示例。你还可以使用 <a href="/zh/UserGuide/Master/API/Programming-JDBC.html">Java JDBC</a> 标准接口执行查询。</p> <ul><li>查询结果的行控制</li></ul> <p>通过使用LIMIT和OFFSET子句，用户可以以与行相关的方式控制查询结果。 我们将通过以下示例演示如何使用LIMIT和OFFSET子句。</p> <ul><li>示例1：基本的LIMIT子句</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status, temperature from root.ln.wf01.wt01 limit 10
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 选择的时间序列是“状态”和“温度”。 SQL语句要求返回查询结果的前10行。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:00:00.000+08:00|                    true|                        25.96|
 |2017-11-01T00:01:00.000+08:00|                    true|                        24.36|
 |2017-11-01T00:02:00.000+08:00|                   false|                        20.09|
 |2017-11-01T00:03:00.000+08:00|                   false|                        20.18|
 |2017-11-01T00:04:00.000+08:00|                   false|                        21.13|
 |2017-11-01T00:05:00.000+08:00|                   false|                        22.72|
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 |2017-11-01T00:08:00.000+08:00|                   false|                        22.58|
 |2017-11-01T00:09:00.000+08:00|                   false|                        20.98|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 10
 It costs 0.000s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br></div></div><ul><li>示例2：带OFFSET的LIMIT子句</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status, temperature from root.ln.wf01.wt01 limit 5 offset 3
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 选择的时间序列是“状态”和“温度”。 SQL语句要求返回查询结果的第3至7行（第一行编号为0行）。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:03:00.000+08:00|                   false|                        20.18|
 |2017-11-01T00:04:00.000+08:00|                   false|                        21.13|
 |2017-11-01T00:05:00.000+08:00|                   false|                        22.72|
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 5
 It costs 0.342s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>示例3：LIMIT子句与WHERE子句结合</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time&lt; 2017-11-01T00:12:00.000 limit 5 offset 3
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 选择的时间序列是“状态”和“温度”。 SQL语句要求返回时间“ 2017-11-01T00：05：00.000”和“ 2017-11-01T00：12：00.000”之间的状态和温度传感器值的第3至4行（第一行） 编号为第0行）。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:03:00.000+08:00|                   false|                        20.18|
 |2017-11-01T00:04:00.000+08:00|                   false|                        21.13|
 |2017-11-01T00:05:00.000+08:00|                   false|                        22.72|
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 5
 It costs 0.000s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>示例4：LIMIT子句与GROUP BY子句组合</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status), max_value(temperature) from root.ln.wf01.wt01 group by ([2017-11-01T00:00:00, 2017-11-07T23:00:00),1d) limit 4 offset 3
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>SQL语句子句要求返回查询结果的第3至6行（第一行编号为0行）。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------------------+----------------------------------------+
 |                         Time|count(root.ln.wf01.wt01.status)|max_value(root.ln.wf01.wt01.temperature)|
 +-----------------------------+-------------------------------+----------------------------------------+
 |2017-11-04T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-05T00:00:00.000+08:00|                           1440|                                    26.0|
 |2017-11-06T00:00:00.000+08:00|                           1440|                                   25.99|
 |2017-11-07T00:00:00.000+08:00|                           1380|                                    26.0|
 +-----------------------------+-------------------------------+----------------------------------------+
 Total line number = 4
 It costs 0.016s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br></div></div><p>值得注意的是，由于当前的FILL子句只能在某个时间点填充时间序列的缺失值，也就是说，FILL子句的执行结果恰好是一行，因此LIMIT和OFFSET不会是 与FILL子句结合使用，否则将提示错误。 例如，执行以下SQL语句：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select temperature from root.sgcc.wf03.wt01 where time = 2017-11-01T16:37:50.000 fill(float[previous, 1m]) limit 10
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>SQL语句将不会执行，并且相应的错误提示如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>Msg: 401: Error occured while parsing SQL to physical plan: line 1:101 mismatched input 'limit' expecting {&lt;EOF&gt;, SLIMIT, SOFFSET, GROUP, DISABLE, ALIGN}
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><ul><li>查询结果的列控制</li></ul> <p>通过使用SLIMIT和SOFFSET子句，用户可以与列相关的方式控制查询结果。 我们将通过以下示例演示如何使用SLIMIT和SOFFSET子句。</p> <ul><li>示例1：基本的SLIMIT子句</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 slimit 1
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 所选时间序列是该设备下的第二列，即温度。 SQL语句要求在&quot;2017-11-01T00:05:00.000&quot;和&quot;2017-11-01T00:12:00.000&quot;的时间点之间选择温度传感器值。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.temperature|
 +-----------------------------+-----------------------------+
 |2017-11-01T00:06:00.000+08:00|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                        21.45|
 |2017-11-01T00:08:00.000+08:00|                        22.58|
 |2017-11-01T00:09:00.000+08:00|                        20.98|
 |2017-11-01T00:10:00.000+08:00|                        25.52|
 |2017-11-01T00:11:00.000+08:00|                        22.91|
 +-----------------------------+-----------------------------+
 Total line number = 6
 It costs 0.000s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><ul><li>示例2：带SOFFSET的SLIMIT子句</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 slimit 1 soffset 1
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 所选时间序列是该设备下的第一列，即电源状态。 SQL语句要求在&quot; 2017-11-01T00:05:00.000&quot;和&quot;2017-11-01T00:12:00.000&quot;的时间点之间选择状态传感器值。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+
 |                         Time|root.ln.wf01.wt01.status|
 +-----------------------------+------------------------+
 |2017-11-01T00:06:00.000+08:00|                   false|
 |2017-11-01T00:07:00.000+08:00|                   false|
 |2017-11-01T00:08:00.000+08:00|                   false|
 |2017-11-01T00:09:00.000+08:00|                   false|
 |2017-11-01T00:10:00.000+08:00|                    true|
 |2017-11-01T00:11:00.000+08:00|                   false|
 +-----------------------------+------------------------+
 Total line number = 6
 It costs 0.003s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><ul><li>示例3：SLIMIT子句与GROUP BY子句结合</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select max_value(*) from root.ln.wf01.wt01 group by ([2017-11-01T00:00:00, 2017-11-07T23:00:00),1d) slimit 1 soffset 1

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------------------------+
 |                         Time|max_value(root.ln.wf01.wt01.status)|
 +-----------------------------+-----------------------------------+
 |2017-11-01T00:00:00.000+08:00|                               true|
 |2017-11-02T00:00:00.000+08:00|                               true|
 |2017-11-03T00:00:00.000+08:00|                               true|
 |2017-11-04T00:00:00.000+08:00|                               true|
 |2017-11-05T00:00:00.000+08:00|                               true|
 |2017-11-06T00:00:00.000+08:00|                               true|
 |2017-11-07T00:00:00.000+08:00|                               true|
 +-----------------------------+-----------------------------------+
 Total line number = 7
 It costs 0.000s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><ul><li>示例4：SLIMIT子句与FILL子句结合</li></ul> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.sgcc.wf03.wt01 where time = 2017-11-01T16:37:50.000 fill(float[previous, 1m]) slimit 1 soffset 1

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------------------+
 |                         Time|root.sgcc.wf03.wt01.status|
 +-----------------------------+--------------------------+
 |2017-11-01T16:35:00.000+08:00|                      true|
 +-----------------------------+--------------------------+
 Total line number = 1
 It costs 0.007s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><ul><li>控制查询结果的行和列</li></ul> <p>除了对查询结果进行行或列控制之外，IoTDB还允许用户控制查询结果的行和列。 这是同时包含LIMIT子句和SLIMIT子句的完整示例。</p> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.ln.wf01.wt01 limit 10 offset 100 slimit 2 soffset 0

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>意思是：</p> <p>所选设备为ln组wf01工厂wt01设备； 所选时间序列是此设备下的第0列至第1列（第一列编号为第0列）。 SQL语句子句要求返回查询结果的第100至109行（第一行编号为0行）。</p> <p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-----------------------------+------------------------+
 |                         Time|root.ln.wf01.wt01.temperature|root.ln.wf01.wt01.status|
 +-----------------------------+-----------------------------+------------------------+
 |2017-11-01T01:40:00.000+08:00|                        21.19|                   false|
 |2017-11-01T01:41:00.000+08:00|                        22.79|                   false|
 |2017-11-01T01:42:00.000+08:00|                        22.98|                   false|
 |2017-11-01T01:43:00.000+08:00|                        21.52|                   false|
 |2017-11-01T01:44:00.000+08:00|                        23.45|                    true|
 |2017-11-01T01:45:00.000+08:00|                        24.06|                    true|
 |2017-11-01T01:46:00.000+08:00|                         22.6|                   false|
 |2017-11-01T01:47:00.000+08:00|                        23.78|                    true|
 |2017-11-01T01:48:00.000+08:00|                        24.72|                    true|
 |2017-11-01T01:49:00.000+08:00|                        24.68|                    true|
 +-----------------------------+-----------------------------+------------------------+
 Total line number = 10
 It costs 0.009s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br></div></div><h4 id="别名"><a href="#别名" class="header-anchor">#</a> 别名</h4> <p>由于 IoTDB 独特的数据模型，在每个传感器前都附带有设备等诸多额外信息。有时，我们只针对某个具体设备查询，而这些前缀信息频繁显示造成了冗余，影响了结果集的显示与分析。这时我们可以使用 IoTDB 提供的 AS 函数，将查询中出现的时间序列给定一个别名。</p> <p>例如：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select s1 as temperature, s2 as speed from root.ln.wf01.wt01;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>则结果集将显示为：</p> <table><thead><tr><th>Time</th> <th>temperature</th> <th>speed</th></tr></thead> <tbody><tr><td>...</td> <td>...</td> <td>...</td></tr></tbody></table> <h4 id="内置函数"><a href="#内置函数" class="header-anchor">#</a> 内置函数</h4> <p>时间序列生成函数可接受若干原始时间序列作为输入，产生一列时间序列输出。与聚合函数不同的是，时间序列生成函数的结果集带有时间戳列。</p> <p>所有的时间序列生成函数都可以接受 * 作为输入，都可以与原始查询混合进行。</p> <ul><li>数学函数</li></ul> <p>目前IoTDB支持下列数学函数，这些数学函数的行为与这些函数在Java Math标准库中对应实现的行为一致。</p> <table><thead><tr><th>函数名</th> <th>输入序列类型</th> <th>输出序列类型</th> <th>Java标准库中的对应实现</th></tr></thead> <tbody><tr><td>SIN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#sin(double)</td></tr> <tr><td>COS</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#cos(double)</td></tr> <tr><td>TAN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#tan(double)</td></tr> <tr><td>ASIN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#asin(double)</td></tr> <tr><td>ACOS</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#acos(double)</td></tr> <tr><td>ATAN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#atan(double)</td></tr> <tr><td>DEGREES</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#toDegrees(double)</td></tr> <tr><td>RADIANS</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#toRadians(double)</td></tr> <tr><td>ABS</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>与输入序列的实际类型一致</td> <td>Math#abs(int) / Math#abs(long) /Math#abs(float) /Math#abs(double)</td></tr> <tr><td>SIGN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#signum(double)</td></tr> <tr><td>CEIL</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#ceil(double)</td></tr> <tr><td>FLOOR</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#floor(double)</td></tr> <tr><td>ROUND</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#rint(double)</td></tr> <tr><td>EXP</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#exp(double)</td></tr> <tr><td>LN</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#log(double)</td></tr> <tr><td>LOG10</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#log10(double)</td></tr> <tr><td>SQRT</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>Math#sqrt(double)</td></tr></tbody></table> <p>例如：</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> s1<span class="token punctuation">,</span> sin<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> cos<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> tan<span class="token punctuation">(</span>s1<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1 <span class="token keyword">limit</span> <span class="token number">5</span> <span class="token keyword">offset</span> <span class="token number">1000</span><span class="token punctuation">;</span>
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------+-------------------+--------------------+-------------------+
 |                         Time|     root.sg1.d1.s1|sin(root.sg1.d1.s1)| cos(root.sg1.d1.s1)|tan(root.sg1.d1.s1)|
 +-----------------------------+-------------------+-------------------+--------------------+-------------------+
 |2020-12-10T17:11:49.037+08:00|7360723084922759782| 0.8133527237573284|  0.5817708713544664| 1.3980636773094157|
 |2020-12-10T17:11:49.038+08:00|4377791063319964531|-0.8938962705202537|  0.4482738644511651| -1.994085181866842|
 |2020-12-10T17:11:49.039+08:00|7972485567734642915| 0.9627757585308978|-0.27030138509681073|-3.5618602479083545|
 |2020-12-10T17:11:49.040+08:00|2508858212791964081|-0.6073417341629443| -0.7944406950452296| 0.7644897069734913|
 |2020-12-10T17:11:49.041+08:00|2817297431185141819|-0.8419358900502509| -0.5395775727782725| 1.5603611649667768|
 +-----------------------------+-------------------+-------------------+--------------------+-------------------+
 Total line number = 5
 It costs 0.008s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>字符串函数</li></ul> <p>目前IoTDB支持下列字符串处理函数：</p> <table><thead><tr><th>函数名</th> <th>输入序列类型</th> <th>必要的属性参数</th> <th>输出序列类型</th> <th>功能描述</th></tr></thead> <tbody><tr><td>STRING_CONTAINS</td> <td>TEXT</td> <td><code>s</code>: 待搜寻的字符串</td> <td>BOOLEAN</td> <td>判断字符串中是否存在<code>s</code></td></tr> <tr><td>STRING_MATCHES</td> <td>TEXT</td> <td><code>regex</code>: Java标准库风格的正则表达式</td> <td>BOOLEAN</td> <td>判断字符串是否能够被正则表达式<code>regex</code>匹配</td></tr></tbody></table> <p>例如：</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> s1<span class="token punctuation">,</span> string_contains<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&quot;s&quot;</span><span class="token operator">=</span><span class="token string">&quot;warn&quot;</span><span class="token punctuation">)</span><span class="token punctuation">,</span> string_matches<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&quot;regex&quot;</span><span class="token operator">=</span><span class="token string">&quot;[^\\s]+37229&quot;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d4<span class="token punctuation">;</span>
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------+-------------------------------------------+------------------------------------------------------+
 |                         Time|root.sg1.d4.s1|string_contains(root.sg1.d4.s1, &quot;s&quot;=&quot;warn&quot;)|string_matches(root.sg1.d4.s1, &quot;regex&quot;=&quot;[^\\s]+37229&quot;)|
 +-----------------------------+--------------+-------------------------------------------+------------------------------------------------------+
 |1970-01-01T08:00:00.001+08:00|    warn:-8721|                                       true|                                                 false|
 |1970-01-01T08:00:00.002+08:00|  error:-37229|                                      false|                                                  true|
 |1970-01-01T08:00:00.003+08:00|     warn:1731|                                       true|                                                 false|
 +-----------------------------+--------------+-------------------------------------------+------------------------------------------------------+
 Total line number = 3
 It costs 0.007s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><ul><li>选择函数</li></ul> <p>目前IoTDB支持如下选择函数：</p> <table><thead><tr><th>函数名</th> <th>输入序列类型</th> <th>必要的属性参数</th> <th>输出序列类型</th> <th>功能描述</th></tr></thead> <tbody><tr><td>TOP_K</td> <td>INT32 / INT64 / FLOAT / DOUBLE / TEXT</td> <td><code>k</code>: 最多选择的数据点数，必须大于0小于等于1000</td> <td>与输入序列的实际类型一致</td> <td>返回某时间序列中值最大的<code>k</code>个数据点。若多于<code>k</code>个数据点的值并列最大，则返回时间戳最小的数据点。</td></tr> <tr><td>BOTTOM_K</td> <td>INT32 / INT64 / FLOAT / DOUBLE / TEXT</td> <td><code>k</code>: 最多选择的数据点数，必须大于0小于等于1000</td> <td>与输入序列的实际类型一致</td> <td>返回某时间序列中值最小的<code>k</code>个数据点。若多于<code>k</code>个数据点的值并列最小，则返回时间戳最小的数据点。</td></tr></tbody></table> <p>例如：</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> s1<span class="token punctuation">,</span> top_k<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&quot;k&quot;</span><span class="token operator">=</span><span class="token string">&quot;2&quot;</span><span class="token punctuation">)</span><span class="token punctuation">,</span> bottom_k<span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token string">&quot;k&quot;</span><span class="token operator">=</span><span class="token string">&quot;2&quot;</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d2 <span class="token keyword">where</span> <span class="token keyword">time</span> <span class="token operator">&gt;</span> <span class="token number">2020</span><span class="token operator">-</span><span class="token number">12</span><span class="token operator">-</span><span class="token number">10</span>T20:<span class="token number">36</span>:<span class="token number">15.530</span><span class="token operator">+</span><span class="token number">08</span>:<span class="token number">00</span><span class="token punctuation">;</span>
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+--------------------+------------------------------+---------------------------------+
 |                         Time|      root.sg1.d2.s1|top_k(root.sg1.d2.s1, &quot;k&quot;=&quot;2&quot;)|bottom_k(root.sg1.d2.s1, &quot;k&quot;=&quot;2&quot;)|
 +-----------------------------+--------------------+------------------------------+---------------------------------+
 |2020-12-10T20:36:15.531+08:00| 1531604122307244742|           1531604122307244742|                             null|
 |2020-12-10T20:36:15.532+08:00|-7426070874923281101|                          null|                             null|
 |2020-12-10T20:36:15.533+08:00|-7162825364312197604|          -7162825364312197604|                             null|
 |2020-12-10T20:36:15.534+08:00|-8581625725655917595|                          null|             -8581625725655917595|
 |2020-12-10T20:36:15.535+08:00|-7667364751255535391|                          null|             -7667364751255535391|
 +-----------------------------+--------------------+------------------------------+---------------------------------+
 Total line number = 5
 It costs 0.006s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>趋势计算函数</li></ul> <p>目前IoTDB支持如下趋势计算函数：</p> <table><thead><tr><th>函数名</th> <th>输入序列类型</th> <th>输出序列类型</th> <th>功能描述</th></tr></thead> <tbody><tr><td>TIME_DIFFERENCE</td> <td>INT32 / INT64 / FLOAT / DOUBLE / BOOLEAN / TEXT</td> <td>INT64</td> <td>统计序列中某数据点的时间戳与前一数据点时间戳的差。范围内第一个数据点没有对应的结果输出。</td></tr> <tr><td>DIFFERENCE</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>与输入序列的实际类型一致</td> <td>统计序列中某数据点的值与前一数据点的值的差。范围内第一个数据点没有对应的结果输出。</td></tr> <tr><td>NON_NEGATIVE_DIFFERENCE</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>与输入序列的实际类型一致</td> <td>统计序列中某数据点的值与前一数据点的值的差的绝对值。范围内第一个数据点没有对应的结果输出。</td></tr> <tr><td>DERIVATIVE</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>统计序列中某数据点相对于前一数据点的变化率，数量上等同于 DIFFERENCE /  TIME_DIFFERENCE。范围内第一个数据点没有对应的结果输出。</td></tr> <tr><td>NON_NEGATIVE_DERIVATIVE</td> <td>INT32 / INT64 / FLOAT / DOUBLE</td> <td>DOUBLE</td> <td>统计序列中某数据点相对于前一数据点的变化率的绝对值，数量上等同于 NON_NEGATIVE_DIFFERENCE /  TIME_DIFFERENCE。范围内第一个数据点没有对应的结果输出。</td></tr></tbody></table> <p>例如：</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> s1<span class="token punctuation">,</span> time_difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> non_negative_difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> derivative<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> non_negative_derivative<span class="token punctuation">(</span>s1<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1 <span class="token keyword">limit</span> <span class="token number">5</span> <span class="token keyword">offset</span> <span class="token number">1000</span><span class="token punctuation">;</span>
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
 |                         Time|     root.sg1.d1.s1|time_difference(root.sg1.d1.s1)|difference(root.sg1.d1.s1)|non_negative_difference(root.sg1.d1.s1)|derivative(root.sg1.d1.s1)|non_negative_derivative(root.sg1.d1.s1)|
 +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
 |2020-12-10T17:11:49.037+08:00|7360723084922759782|                              1|      -8431715764844238876|                    8431715764844238876|    -8.4317157648442388E18|                  8.4317157648442388E18|
 |2020-12-10T17:11:49.038+08:00|4377791063319964531|                              1|      -2982932021602795251|                    2982932021602795251|     -2.982932021602795E18|                   2.982932021602795E18|
 |2020-12-10T17:11:49.039+08:00|7972485567734642915|                              1|       3594694504414678384|                    3594694504414678384|     3.5946945044146785E18|                  3.5946945044146785E18|
 |2020-12-10T17:11:49.040+08:00|2508858212791964081|                              1|      -5463627354942678834|                    5463627354942678834|     -5.463627354942679E18|                   5.463627354942679E18|
 |2020-12-10T17:11:49.041+08:00|2817297431185141819|                              1|        308439218393177738|                     308439218393177738|     3.0843921839317773E17|                  3.0843921839317773E17|
 +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
 Total line number = 5
 It costs 0.014s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><ul><li>自定义序列生成函数</li></ul> <p>请参考 <a href="/zh/UserGuide/Master/UDF/UDF-User-Defined-Function.html">UDF (用户定义函数)</a>。</p> <h4 id="错误处理"><a href="#错误处理" class="header-anchor">#</a> 错误处理</h4> <p>当LIMIT / SLIMIT的参数N / SN超过结果集的大小时，IoTDB将按预期返回所有结果。 例如，原始SQL语句的查询结果由六行组成，我们通过LIMIT子句选择前100行：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 limit 100

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
 |                         Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +-----------------------------+------------------------+-----------------------------+
 |2017-11-01T00:06:00.000+08:00|                   false|                        20.71|
 |2017-11-01T00:07:00.000+08:00|                   false|                        21.45|
 |2017-11-01T00:08:00.000+08:00|                   false|                        22.58|
 |2017-11-01T00:09:00.000+08:00|                   false|                        20.98|
 |2017-11-01T00:10:00.000+08:00|                    true|                        25.52|
 |2017-11-01T00:11:00.000+08:00|                   false|                        22.91|
 +-----------------------------+------------------------+-----------------------------+
 Total line number = 6
 It costs 0.005s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><p>当LIMIT / SLIMIT子句的参数N / SN超过允许的最大值（N / SN的类型为int32）时，系统将提示错误。 例如，执行以下SQL语句：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 limit 1234567890123456789

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>SQL语句将不会执行，并且相应的错误提示如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>Msg: 303: check metadata error: Out of range. LIMIT &lt;N&gt;: N should be Int32.
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>当LIMIT / LIMIT子句的参数N / SN不是正整数时，系统将提示错误。 例如，执行以下SQL语句：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 limit 13.1

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>SQL语句将不会执行，并且相应的错误提示如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>Msg: 401: line 1:129 mismatched input '.' expecting {&lt;EOF&gt;, SLIMIT, OFFSET, SOFFSET, GROUP, DISABLE, ALIGN}
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>当LIMIT子句的参数OFFSET超过结果集的大小时，IoTDB将返回空结果集。 例如，执行以下SQL语句：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select status,temperature from root.ln.wf01.wt01 where time &gt; 2017-11-01T00:05:00.000 and time &lt; 2017-11-01T00:12:00.000 limit 2 offset 6

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果如下所示：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>+----+------------------------+-----------------------------+
 |Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
 +----+------------------------+-----------------------------+
 +----+------------------------+-----------------------------+
 Empty set.
 It costs 0.005s
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><h3 id="数据删除"><a href="#数据删除" class="header-anchor">#</a> 数据删除</h3> <p>用户使用<a href="/zh/UserGuide/Master/Appendix/SQL-Reference.html">DELETE语句</a>可以删除指定的时间序列中符合时间删除条件的数据。在删除数据时，用户可以选择需要删除的一个或多个时间序列、时间序列的前缀、时间序列带*路径对某一个时间区间内的数据进行删除。</p> <p>在JAVA编程环境中，您可以使用JDBC API单条或批量执行DELETE语句。</p> <h4 id="单传感器时间序列值删除"><a href="#单传感器时间序列值删除" class="header-anchor">#</a> 单传感器时间序列值删除</h4> <p>以测控ln集团为例，存在这样的使用场景：</p> <p>wf02子站的wt02设备在2017-11-01 16:26:00之前的供电状态出现多段错误，且无法分析其正确数据，错误数据影响了与其他设备的关联分析。此时，需要将此时间段前的数据删除。进行此操作的SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02.status where time&lt;=2017-11-01T16:26:00;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>如果我们仅仅想要删除2017年内的在2017-11-01 16:26:00之前的数据，可以使用以下SQL:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02.status where time&gt;=2017-01-01T00:00:00 and time&lt;=2017-11-01T16:26:00;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>IoTDB 支持删除一个时间序列任何一个时间范围内的所有时序点，用户可以使用以下SQL语句指定需要删除的时间范围：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02.status where time &lt; 10
 delete from root.ln.wf02.wt02.status where time &lt;= 10
 delete from root.ln.wf02.wt02.status where time &lt; 20 and time &gt; 10
 delete from root.ln.wf02.wt02.status where time &lt;= 20 and time &gt;= 10
 delete from root.ln.wf02.wt02.status where time &gt; 20
 delete from root.ln.wf02.wt02.status where time &gt;= 20
 delete from root.ln.wf02.wt02.status where time = 20
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p>需要注意，当前的删除语句不支持where子句后的时间范围为多个由OR连接成的时间区间。如下删除语句将会解析出错：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02.status where time &gt; 4 or time &lt; 0
 Msg: 303: Check metadata error: For delete statement, where clause can only contain atomic
 expressions like : time &gt; XXX, time &lt;= XXX, or two atomic expressions connected by 'AND'
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><p>如果delete语句中未指定where子句，则会删除时间序列中的所有数据。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.status
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><h4 id="多传感器时间序列值删除"><a href="#多传感器时间序列值删除" class="header-anchor">#</a> 多传感器时间序列值删除</h4> <p>当ln集团wf02子站的wt02设备在2017-11-01 16:26:00之前的供电状态和设备硬件版本都需要删除，此时可以使用含义更广的<a href="/zh/UserGuide/Master/Data-Concept/Data-Model-and-Terminology.html">前缀路径或带<code>*</code>路径</a>进行删除操作，进行此操作的SQL语句为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02 where time &lt;= 2017-11-01T16:26:00;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>或</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>delete from root.ln.wf02.wt02.* where time &lt;= 2017-11-01T16:26:00;
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>需要注意的是，当删除的路径不存在时，IoTDB会提示路径不存在，无法删除数据，如下所示。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB&gt; delete from root.ln.wf03.wt02.status where time &lt; now()
 Msg: TimeSeries does not exist and its data cannot be deleted
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><h4 id="删除时间分区-实验性功能"><a href="#删除时间分区-实验性功能" class="header-anchor">#</a> 删除时间分区 (实验性功能)</h4> <p>您可以通过如下语句来删除某一个存储组下的指定时间分区:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>DELETE PARTITION root.ln 0,1,2
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>上例中的0,1,2为待删除时间分区的id，您可以通过查看IoTDB的数据文件夹找到它，或者可以通过计算<code>timestamp / partitionInterval</code>(向下取整),
 手动地将一个时间戳转换为对应的id，其中的<code>partitionInterval</code>可以在IoTDB的配置文件中找到（如果您使用的版本支持时间分区）。</p> <p>请注意该功能目前只是实验性的，如果您不是开发者，使用时请务必谨慎。</p></div> <div class="page-nav"><p class="inner"><span class="prev">
         ←
         <a href="/zh/UserGuide/Master/IoTDB-SQL-Language/DDL-Data-Definition-Language.html" class="prev">
           数据定义语言（DDL）
         </a></span> <span class="next"><a href="/zh/UserGuide/Master/IoTDB-SQL-Language/Maintenance-Command.html">
           运维命令
         </a>
         →
       </span></p></div> <p style="text-align: center;">Copyright © 2021 The Apache Software Foundation.<br>
      Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p> <p style="text-align: center; margin-top: 10px; color: #444">
     Contact us: Join QQ Group 659990460 | Add friend <i>tietouqiao</i> and be invited to Wechat Group<br>
     see <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> for more</p></main></div><div class="global-ui"></div></div>
     <script src="/assets/js/app.2be61c67.js" defer></script><script src="/assets/js/3.76c26675.js" defer></script><script src="/assets/js/405.80826ea1.js" defer></script>
   </body>
 </html>