zh/UserGuide/Master/Operation Manual/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 1.7.1">
     <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.679f71b6.css" as="style"><link rel="preload" href="/assets/js/app.a12b5307.js" as="script"><link rel="preload" href="/assets/js/3.49f0f20a.js" as="script"><link rel="preload" href="/assets/js/341.626acd05.js" as="script"><link rel="prefetch" href="/assets/js/10.a9e4399a.js"><link rel="prefetch" href="/assets/js/100.4b5f6322.js"><link rel="prefetch" href="/assets/js/101.42aa5b0b.js"><link rel="prefetch" href="/assets/js/102.bfeec1ea.js"><link rel="prefetch" href="/assets/js/103.df833354.js"><link rel="prefetch" href="/assets/js/104.048c0f09.js"><link rel="prefetch" href="/assets/js/105.c452fad7.js"><link rel="prefetch" href="/assets/js/106.9224b929.js"><link rel="prefetch" href="/assets/js/107.73f1e6e7.js"><link rel="prefetch" href="/assets/js/108.00467fff.js"><link rel="prefetch" href="/assets/js/109.9f69cdc4.js"><link rel="prefetch" href="/assets/js/11.43ba1aca.js"><link rel="prefetch" href="/assets/js/110.78abf220.js"><link rel="prefetch" href="/assets/js/111.f004fa98.js"><link rel="prefetch" href="/assets/js/112.59735d56.js"><link rel="prefetch" href="/assets/js/113.ee4aacbc.js"><link rel="prefetch" href="/assets/js/114.7fa3a420.js"><link rel="prefetch" href="/assets/js/115.91dfcb8c.js"><link rel="prefetch" href="/assets/js/116.a5c73299.js"><link rel="prefetch" href="/assets/js/117.1bac72d6.js"><link rel="prefetch" href="/assets/js/118.f4277c6c.js"><link rel="prefetch" href="/assets/js/119.0c402f7d.js"><link rel="prefetch" href="/assets/js/12.af3ddb51.js"><link rel="prefetch" href="/assets/js/120.1c09fd00.js"><link rel="prefetch" href="/assets/js/121.90eb132d.js"><link rel="prefetch" href="/assets/js/122.b844327f.js"><link rel="prefetch" href="/assets/js/123.55abda20.js"><link rel="prefetch" href="/assets/js/124.d3c9f762.js"><link rel="prefetch" href="/assets/js/125.8476be66.js"><link rel="prefetch" href="/assets/js/126.2777f680.js"><link rel="prefetch" href="/assets/js/127.8cffacc2.js"><link rel="prefetch" href="/assets/js/128.f3c282b6.js"><link rel="prefetch" href="/assets/js/129.2aea930e.js"><link rel="prefetch" href="/assets/js/13.351ae2e3.js"><link rel="prefetch" href="/assets/js/130.fb57ea4d.js"><link rel="prefetch" href="/assets/js/131.0c6ee1c8.js"><link rel="prefetch" href="/assets/js/132.e22d327d.js"><link rel="prefetch" href="/assets/js/133.266018b0.js"><link rel="prefetch" href="/assets/js/134.15fb436c.js"><link rel="prefetch" href="/assets/js/135.e64131ed.js"><link rel="prefetch" href="/assets/js/136.42099e64.js"><link rel="prefetch" href="/assets/js/137.f874ca52.js"><link rel="prefetch" href="/assets/js/138.1fb71947.js"><link rel="prefetch" href="/assets/js/139.dc5711fc.js"><link rel="prefetch" href="/assets/js/14.1f820e1c.js"><link rel="prefetch" href="/assets/js/140.1b69fe74.js"><link rel="prefetch" href="/assets/js/141.46dfed23.js"><link rel="prefetch" href="/assets/js/142.ae452fb7.js"><link rel="prefetch" href="/assets/js/143.f7e83f27.js"><link rel="prefetch" href="/assets/js/144.8bad0645.js"><link rel="prefetch" href="/assets/js/145.00d3df1f.js"><link rel="prefetch" href="/assets/js/146.2cc9442a.js"><link rel="prefetch" href="/assets/js/147.0b488cbf.js"><link rel="prefetch" href="/assets/js/148.4e10cebd.js"><link rel="prefetch" href="/assets/js/149.d06c48d1.js"><link rel="prefetch" href="/assets/js/15.e2df8f28.js"><link rel="prefetch" href="/assets/js/150.e5bf8dc4.js"><link rel="prefetch" href="/assets/js/151.e6182d49.js"><link rel="prefetch" href="/assets/js/152.d1ca9877.js"><link rel="prefetch" href="/assets/js/153.2d9f0adc.js"><link rel="prefetch" href="/assets/js/154.a573c85a.js"><link rel="prefetch" href="/assets/js/155.7c7ecf29.js"><link rel="prefetch" href="/assets/js/156.62ee83e7.js"><link rel="prefetch" href="/assets/js/157.6669fb0c.js"><link rel="prefetch" href="/assets/js/158.cd096604.js"><link rel="prefetch" href="/assets/js/159.5e4dfdd7.js"><link rel="prefetch" href="/assets/js/16.9d83cb2c.js"><link rel="prefetch" href="/assets/js/160.f5cf2383.js"><link rel="prefetch" href="/assets/js/161.ca7e326f.js"><link rel="prefetch" href="/assets/js/162.4e479af2.js"><link rel="prefetch" href="/assets/js/163.cf62e1af.js"><link rel="prefetch" href="/assets/js/164.113484ca.js"><link rel="prefetch" href="/assets/js/165.1d2a7728.js"><link rel="prefetch" href="/assets/js/166.ec59b713.js"><link rel="prefetch" href="/assets/js/167.ac1b5d5d.js"><link rel="prefetch" href="/assets/js/168.f9d31ebb.js"><link rel="prefetch" href="/assets/js/169.afb45ad3.js"><link rel="prefetch" href="/assets/js/17.49e50ea2.js"><link rel="prefetch" href="/assets/js/170.71184a9e.js"><link rel="prefetch" href="/assets/js/171.42cd0c24.js"><link rel="prefetch" href="/assets/js/172.40343320.js"><link rel="prefetch" href="/assets/js/173.7fb3ac43.js"><link rel="prefetch" href="/assets/js/174.1d88db84.js"><link rel="prefetch" href="/assets/js/175.ec498db4.js"><link rel="prefetch" href="/assets/js/176.2470317b.js"><link rel="prefetch" href="/assets/js/177.e55600de.js"><link rel="prefetch" href="/assets/js/178.6a930da8.js"><link rel="prefetch" href="/assets/js/179.1b39fb7a.js"><link rel="prefetch" href="/assets/js/18.522bd806.js"><link rel="prefetch" href="/assets/js/180.69cdb354.js"><link rel="prefetch" href="/assets/js/181.5a28d2eb.js"><link rel="prefetch" href="/assets/js/182.d412e464.js"><link rel="prefetch" href="/assets/js/183.dafb377f.js"><link rel="prefetch" href="/assets/js/184.d4401418.js"><link rel="prefetch" href="/assets/js/185.65289f4c.js"><link rel="prefetch" href="/assets/js/186.ee6fc0b5.js"><link rel="prefetch" href="/assets/js/187.e0da8267.js"><link rel="prefetch" href="/assets/js/188.1bc563de.js"><link rel="prefetch" href="/assets/js/189.476347bd.js"><link rel="prefetch" href="/assets/js/19.cfbee5e5.js"><link rel="prefetch" href="/assets/js/190.9ce4e1d7.js"><link rel="prefetch" href="/assets/js/191.6ba979e7.js"><link rel="prefetch" href="/assets/js/192.e84c90e8.js"><link rel="prefetch" href="/assets/js/193.23a788b3.js"><link rel="prefetch" href="/assets/js/194.2cc1dd44.js"><link rel="prefetch" href="/assets/js/195.9ea38b07.js"><link rel="prefetch" href="/assets/js/196.5745ed39.js"><link rel="prefetch" href="/assets/js/197.57267595.js"><link rel="prefetch" href="/assets/js/198.a2857499.js"><link rel="prefetch" href="/assets/js/199.99d68945.js"><link rel="prefetch" href="/assets/js/20.4bdfbbe8.js"><link rel="prefetch" href="/assets/js/200.5c0f60ac.js"><link rel="prefetch" href="/assets/js/201.dc0c8c2b.js"><link rel="prefetch" href="/assets/js/202.23a01d12.js"><link rel="prefetch" href="/assets/js/203.bb31217f.js"><link rel="prefetch" href="/assets/js/204.17a33dc0.js"><link rel="prefetch" href="/assets/js/205.a15dd906.js"><link rel="prefetch" href="/assets/js/206.84f38d54.js"><link rel="prefetch" href="/assets/js/207.ad8df2fa.js"><link rel="prefetch" href="/assets/js/208.57df0491.js"><link rel="prefetch" href="/assets/js/209.9f1d553d.js"><link rel="prefetch" href="/assets/js/21.851eb8b7.js"><link rel="prefetch" href="/assets/js/210.f935b769.js"><link rel="prefetch" href="/assets/js/211.506467a2.js"><link rel="prefetch" href="/assets/js/212.58502315.js"><link rel="prefetch" href="/assets/js/213.de168e28.js"><link rel="prefetch" href="/assets/js/214.fdcca01d.js"><link rel="prefetch" href="/assets/js/215.7dceea98.js"><link rel="prefetch" href="/assets/js/216.6d4b93b5.js"><link rel="prefetch" href="/assets/js/217.9fcdec6d.js"><link rel="prefetch" href="/assets/js/218.c0d65c69.js"><link rel="prefetch" href="/assets/js/219.46602b01.js"><link rel="prefetch" href="/assets/js/22.ab7a2af8.js"><link rel="prefetch" href="/assets/js/220.1fb41856.js"><link rel="prefetch" href="/assets/js/221.b8e25f57.js"><link rel="prefetch" href="/assets/js/222.a346f7f6.js"><link rel="prefetch" href="/assets/js/223.75ed8115.js"><link rel="prefetch" href="/assets/js/224.69654b05.js"><link rel="prefetch" href="/assets/js/225.785764ce.js"><link rel="prefetch" href="/assets/js/226.537bd668.js"><link rel="prefetch" href="/assets/js/227.b838c577.js"><link rel="prefetch" href="/assets/js/228.8ed5da41.js"><link rel="prefetch" href="/assets/js/229.90bf4abc.js"><link rel="prefetch" href="/assets/js/23.88a22028.js"><link rel="prefetch" href="/assets/js/230.ed53603c.js"><link rel="prefetch" href="/assets/js/231.056674cd.js"><link rel="prefetch" href="/assets/js/232.7a19684c.js"><link rel="prefetch" href="/assets/js/233.537039d9.js"><link rel="prefetch" href="/assets/js/234.46196705.js"><link rel="prefetch" href="/assets/js/235.1b871a5b.js"><link rel="prefetch" href="/assets/js/236.7e237f16.js"><link rel="prefetch" href="/assets/js/237.6c633b04.js"><link rel="prefetch" href="/assets/js/238.0473bef9.js"><link rel="prefetch" href="/assets/js/239.6d32dc93.js"><link rel="prefetch" href="/assets/js/24.d23292bc.js"><link rel="prefetch" href="/assets/js/240.522a8746.js"><link rel="prefetch" href="/assets/js/241.6d6149e4.js"><link rel="prefetch" href="/assets/js/242.1217edbd.js"><link rel="prefetch" href="/assets/js/243.99da6819.js"><link rel="prefetch" href="/assets/js/244.7c4305a5.js"><link rel="prefetch" href="/assets/js/245.971feebe.js"><link rel="prefetch" href="/assets/js/246.89298634.js"><link rel="prefetch" href="/assets/js/247.605d7f5a.js"><link rel="prefetch" href="/assets/js/248.49a6c586.js"><link rel="prefetch" href="/assets/js/249.5167dd30.js"><link rel="prefetch" href="/assets/js/25.bc6a97e8.js"><link rel="prefetch" href="/assets/js/250.b238b8a3.js"><link rel="prefetch" href="/assets/js/251.9f562870.js"><link rel="prefetch" href="/assets/js/252.20b346f2.js"><link rel="prefetch" href="/assets/js/253.09cc69fd.js"><link rel="prefetch" href="/assets/js/254.a0a9e348.js"><link rel="prefetch" href="/assets/js/255.4cd0e8f1.js"><link rel="prefetch" href="/assets/js/256.5d033761.js"><link rel="prefetch" href="/assets/js/257.26160db0.js"><link rel="prefetch" href="/assets/js/258.93920bc8.js"><link rel="prefetch" href="/assets/js/259.5b840cc9.js"><link rel="prefetch" href="/assets/js/26.fbaaabfb.js"><link rel="prefetch" href="/assets/js/260.7d56b9c7.js"><link rel="prefetch" href="/assets/js/261.2be46719.js"><link rel="prefetch" href="/assets/js/262.8017ea9a.js"><link rel="prefetch" href="/assets/js/263.3151ff24.js"><link rel="prefetch" href="/assets/js/264.49aca677.js"><link rel="prefetch" href="/assets/js/265.bb90b170.js"><link rel="prefetch" href="/assets/js/266.55f4e29e.js"><link rel="prefetch" href="/assets/js/267.05c3ddec.js"><link rel="prefetch" href="/assets/js/268.453fe398.js"><link rel="prefetch" href="/assets/js/269.0a2935b6.js"><link rel="prefetch" href="/assets/js/27.0b57c820.js"><link rel="prefetch" href="/assets/js/270.c71ff59b.js"><link rel="prefetch" href="/assets/js/271.d28f5462.js"><link rel="prefetch" href="/assets/js/272.0f0a07d7.js"><link rel="prefetch" href="/assets/js/273.a8c5a865.js"><link rel="prefetch" href="/assets/js/274.3903673e.js"><link rel="prefetch" href="/assets/js/275.5a377690.js"><link rel="prefetch" href="/assets/js/276.a47bf30c.js"><link rel="prefetch" href="/assets/js/277.2c97f2c5.js"><link rel="prefetch" href="/assets/js/278.2f85f46c.js"><link rel="prefetch" href="/assets/js/279.4b1deb2e.js"><link rel="prefetch" href="/assets/js/28.902cf242.js"><link rel="prefetch" href="/assets/js/280.9af31918.js"><link rel="prefetch" href="/assets/js/281.b06cbabc.js"><link rel="prefetch" href="/assets/js/282.998c4254.js"><link rel="prefetch" href="/assets/js/283.65c16c23.js"><link rel="prefetch" href="/assets/js/284.88880c84.js"><link rel="prefetch" href="/assets/js/285.b14f9667.js"><link rel="prefetch" href="/assets/js/286.c3c3811e.js"><link rel="prefetch" href="/assets/js/287.47613b0c.js"><link rel="prefetch" href="/assets/js/288.5737dd0a.js"><link rel="prefetch" href="/assets/js/289.0bb3ac1c.js"><link rel="prefetch" href="/assets/js/29.8878a84b.js"><link rel="prefetch" href="/assets/js/290.d8bd9f13.js"><link rel="prefetch" href="/assets/js/291.d8da4ced.js"><link rel="prefetch" href="/assets/js/292.f22b2fc1.js"><link rel="prefetch" href="/assets/js/293.29a5f319.js"><link rel="prefetch" href="/assets/js/294.c24273e9.js"><link rel="prefetch" href="/assets/js/295.19032576.js"><link rel="prefetch" href="/assets/js/296.aede5c28.js"><link rel="prefetch" href="/assets/js/297.bcc6ae09.js"><link rel="prefetch" href="/assets/js/298.ae18a3c8.js"><link rel="prefetch" href="/assets/js/299.e643abb2.js"><link rel="prefetch" href="/assets/js/30.db844a98.js"><link rel="prefetch" href="/assets/js/300.0c3a88f8.js"><link rel="prefetch" href="/assets/js/301.cb0c4e3c.js"><link rel="prefetch" href="/assets/js/302.b9b5e0de.js"><link rel="prefetch" href="/assets/js/303.b2b08e58.js"><link rel="prefetch" href="/assets/js/304.6a8beaa0.js"><link rel="prefetch" href="/assets/js/305.d9b417c0.js"><link rel="prefetch" href="/assets/js/306.a176e286.js"><link rel="prefetch" href="/assets/js/307.4ca102ed.js"><link rel="prefetch" href="/assets/js/308.9d7acc5b.js"><link rel="prefetch" href="/assets/js/309.4bd88c45.js"><link rel="prefetch" href="/assets/js/31.726da8fb.js"><link rel="prefetch" href="/assets/js/310.8be7df64.js"><link rel="prefetch" href="/assets/js/311.d3d5d934.js"><link rel="prefetch" href="/assets/js/312.ea1f6a7f.js"><link rel="prefetch" href="/assets/js/313.bb4b6aca.js"><link rel="prefetch" href="/assets/js/314.1d1c4993.js"><link rel="prefetch" href="/assets/js/315.7c0d34c3.js"><link rel="prefetch" href="/assets/js/316.9e5c04ed.js"><link rel="prefetch" href="/assets/js/317.dc080175.js"><link rel="prefetch" href="/assets/js/318.a5eb57af.js"><link rel="prefetch" href="/assets/js/319.5f132fa7.js"><link rel="prefetch" href="/assets/js/32.bad93e79.js"><link rel="prefetch" href="/assets/js/320.d5dff770.js"><link rel="prefetch" href="/assets/js/321.1f402a86.js"><link rel="prefetch" href="/assets/js/322.d27214d8.js"><link rel="prefetch" href="/assets/js/323.3181e658.js"><link rel="prefetch" href="/assets/js/324.f395be90.js"><link rel="prefetch" href="/assets/js/325.90778fc6.js"><link rel="prefetch" href="/assets/js/326.9e5584da.js"><link rel="prefetch" href="/assets/js/327.f732b4a7.js"><link rel="prefetch" href="/assets/js/328.2462b58c.js"><link rel="prefetch" href="/assets/js/329.4517899a.js"><link rel="prefetch" href="/assets/js/33.00e7d6b5.js"><link rel="prefetch" href="/assets/js/330.fe63dd75.js"><link rel="prefetch" href="/assets/js/331.48c267b1.js"><link rel="prefetch" href="/assets/js/332.5f95316f.js"><link rel="prefetch" href="/assets/js/333.50357d27.js"><link rel="prefetch" href="/assets/js/334.ab9e3cfe.js"><link rel="prefetch" href="/assets/js/335.dd642cd4.js"><link rel="prefetch" href="/assets/js/336.0bbc8887.js"><link rel="prefetch" href="/assets/js/337.81529dc2.js"><link rel="prefetch" href="/assets/js/338.4089f17d.js"><link rel="prefetch" href="/assets/js/339.a1b8263d.js"><link rel="prefetch" href="/assets/js/34.44ac5494.js"><link rel="prefetch" href="/assets/js/340.6d1f6815.js"><link rel="prefetch" href="/assets/js/342.557c9c35.js"><link rel="prefetch" href="/assets/js/343.a9c0b30c.js"><link rel="prefetch" href="/assets/js/344.dea6404e.js"><link rel="prefetch" href="/assets/js/345.b9dabeb8.js"><link rel="prefetch" href="/assets/js/346.ed03f1f5.js"><link rel="prefetch" href="/assets/js/347.6556794f.js"><link rel="prefetch" href="/assets/js/348.4886e7f3.js"><link rel="prefetch" href="/assets/js/349.c83494d9.js"><link rel="prefetch" href="/assets/js/35.7f32ce73.js"><link rel="prefetch" href="/assets/js/350.743c2c22.js"><link rel="prefetch" href="/assets/js/351.09f4b30e.js"><link rel="prefetch" href="/assets/js/352.25798214.js"><link rel="prefetch" href="/assets/js/353.26b227c3.js"><link rel="prefetch" href="/assets/js/354.f1e4a1e6.js"><link rel="prefetch" href="/assets/js/355.124b541f.js"><link rel="prefetch" href="/assets/js/356.0f8c88cc.js"><link rel="prefetch" href="/assets/js/357.94de66d9.js"><link rel="prefetch" href="/assets/js/358.9ec1f1c5.js"><link rel="prefetch" href="/assets/js/359.bceb8b18.js"><link rel="prefetch" href="/assets/js/36.d1e9d19f.js"><link rel="prefetch" href="/assets/js/360.90e3173d.js"><link rel="prefetch" href="/assets/js/361.6e5b94ba.js"><link rel="prefetch" href="/assets/js/362.13e70eac.js"><link rel="prefetch" href="/assets/js/363.f5e26cbd.js"><link rel="prefetch" href="/assets/js/364.ddeeadcb.js"><link rel="prefetch" href="/assets/js/365.7618548f.js"><link rel="prefetch" href="/assets/js/366.4c1f28a4.js"><link rel="prefetch" href="/assets/js/367.84c7b5cb.js"><link rel="prefetch" href="/assets/js/368.6ba68b87.js"><link rel="prefetch" href="/assets/js/369.ac394e0b.js"><link rel="prefetch" href="/assets/js/37.3351af87.js"><link rel="prefetch" href="/assets/js/370.ddf01dea.js"><link rel="prefetch" href="/assets/js/371.6e846e97.js"><link rel="prefetch" href="/assets/js/372.967bc3e0.js"><link rel="prefetch" href="/assets/js/373.d737a92d.js"><link rel="prefetch" href="/assets/js/374.cbf3648a.js"><link rel="prefetch" href="/assets/js/375.7d3c8252.js"><link rel="prefetch" href="/assets/js/376.0683cfdb.js"><link rel="prefetch" href="/assets/js/377.aaa95bcd.js"><link rel="prefetch" href="/assets/js/378.031f4c19.js"><link rel="prefetch" href="/assets/js/379.27d891cf.js"><link rel="prefetch" href="/assets/js/38.2334aea2.js"><link rel="prefetch" href="/assets/js/380.99d33fcb.js"><link rel="prefetch" href="/assets/js/381.cd4c8153.js"><link rel="prefetch" href="/assets/js/382.72973fb7.js"><link rel="prefetch" href="/assets/js/383.50468482.js"><link rel="prefetch" href="/assets/js/384.39179664.js"><link rel="prefetch" href="/assets/js/385.38fc09d3.js"><link rel="prefetch" href="/assets/js/386.f0785215.js"><link rel="prefetch" href="/assets/js/387.b11cd3b5.js"><link rel="prefetch" href="/assets/js/388.da5e7587.js"><link rel="prefetch" href="/assets/js/389.d70d34ac.js"><link rel="prefetch" href="/assets/js/39.683bc07a.js"><link rel="prefetch" href="/assets/js/390.d0e96c54.js"><link rel="prefetch" href="/assets/js/391.0de12f2c.js"><link rel="prefetch" href="/assets/js/392.43dea516.js"><link rel="prefetch" href="/assets/js/393.09fef64b.js"><link rel="prefetch" href="/assets/js/394.9238cc28.js"><link rel="prefetch" href="/assets/js/395.e45827ba.js"><link rel="prefetch" href="/assets/js/396.534abd81.js"><link rel="prefetch" href="/assets/js/397.e24dbd64.js"><link rel="prefetch" href="/assets/js/398.13484bba.js"><link rel="prefetch" href="/assets/js/399.76ec8e7c.js"><link rel="prefetch" href="/assets/js/4.06d2a3f5.js"><link rel="prefetch" href="/assets/js/40.829e9e65.js"><link rel="prefetch" href="/assets/js/400.06048cef.js"><link rel="prefetch" href="/assets/js/401.3aae5fae.js"><link rel="prefetch" href="/assets/js/402.11c5e2ca.js"><link rel="prefetch" href="/assets/js/403.23f6c085.js"><link rel="prefetch" href="/assets/js/404.eca12328.js"><link rel="prefetch" href="/assets/js/405.adf23f5b.js"><link rel="prefetch" href="/assets/js/406.0d95cbf4.js"><link rel="prefetch" href="/assets/js/407.c5c902cf.js"><link rel="prefetch" href="/assets/js/408.4e3789ec.js"><link rel="prefetch" href="/assets/js/409.c7fd46f6.js"><link rel="prefetch" href="/assets/js/41.ae8c3e94.js"><link rel="prefetch" href="/assets/js/410.5561837c.js"><link rel="prefetch" href="/assets/js/411.c8813216.js"><link rel="prefetch" href="/assets/js/412.3e422c85.js"><link rel="prefetch" href="/assets/js/413.72a1502a.js"><link rel="prefetch" href="/assets/js/414.812ba53a.js"><link rel="prefetch" href="/assets/js/415.699344c0.js"><link rel="prefetch" href="/assets/js/416.22028a1c.js"><link rel="prefetch" href="/assets/js/417.545238a2.js"><link rel="prefetch" href="/assets/js/418.ec3fa2c9.js"><link rel="prefetch" href="/assets/js/419.8252aa9a.js"><link rel="prefetch" href="/assets/js/42.45821720.js"><link rel="prefetch" href="/assets/js/420.7fd12e8f.js"><link rel="prefetch" href="/assets/js/421.034d8e57.js"><link rel="prefetch" href="/assets/js/422.58fd02e5.js"><link rel="prefetch" href="/assets/js/423.0efb5cca.js"><link rel="prefetch" href="/assets/js/424.cf690231.js"><link rel="prefetch" href="/assets/js/425.a8023769.js"><link rel="prefetch" href="/assets/js/426.f8544cb1.js"><link rel="prefetch" href="/assets/js/427.e7ae9d71.js"><link rel="prefetch" href="/assets/js/428.f5ca9583.js"><link rel="prefetch" href="/assets/js/429.55f35b32.js"><link rel="prefetch" href="/assets/js/43.bd27e7b5.js"><link rel="prefetch" href="/assets/js/430.653f9e38.js"><link rel="prefetch" href="/assets/js/431.bf6a087a.js"><link rel="prefetch" href="/assets/js/432.af707c18.js"><link rel="prefetch" href="/assets/js/433.a67268ba.js"><link rel="prefetch" href="/assets/js/434.7e3731d1.js"><link rel="prefetch" href="/assets/js/435.6082c268.js"><link rel="prefetch" href="/assets/js/436.67e746d2.js"><link rel="prefetch" href="/assets/js/437.72bc06d2.js"><link rel="prefetch" href="/assets/js/438.49f87916.js"><link rel="prefetch" href="/assets/js/439.40a41e1a.js"><link rel="prefetch" href="/assets/js/44.e0cd7e7b.js"><link rel="prefetch" href="/assets/js/440.71bb7390.js"><link rel="prefetch" href="/assets/js/441.e377be02.js"><link rel="prefetch" href="/assets/js/442.16738a41.js"><link rel="prefetch" href="/assets/js/443.ff133e10.js"><link rel="prefetch" href="/assets/js/444.b69ccc89.js"><link rel="prefetch" href="/assets/js/445.81d07e0e.js"><link rel="prefetch" href="/assets/js/446.c6c8be6f.js"><link rel="prefetch" href="/assets/js/447.00d171da.js"><link rel="prefetch" href="/assets/js/448.6fd3f02e.js"><link rel="prefetch" href="/assets/js/449.cb2c50b5.js"><link rel="prefetch" href="/assets/js/45.fa02a8c0.js"><link rel="prefetch" href="/assets/js/450.958bd0f9.js"><link rel="prefetch" href="/assets/js/451.92817c30.js"><link rel="prefetch" href="/assets/js/452.5a896c19.js"><link rel="prefetch" href="/assets/js/453.57aa9ce2.js"><link rel="prefetch" href="/assets/js/454.bf11ac3f.js"><link rel="prefetch" href="/assets/js/455.04eaff85.js"><link rel="prefetch" href="/assets/js/456.b2919005.js"><link rel="prefetch" href="/assets/js/457.80a3300a.js"><link rel="prefetch" href="/assets/js/458.a0ed6f4a.js"><link rel="prefetch" href="/assets/js/459.70eb98ab.js"><link rel="prefetch" href="/assets/js/46.cfcdcea2.js"><link rel="prefetch" href="/assets/js/460.beb14272.js"><link rel="prefetch" href="/assets/js/461.bda77b92.js"><link rel="prefetch" href="/assets/js/462.d1c99720.js"><link rel="prefetch" href="/assets/js/463.011dd91d.js"><link rel="prefetch" href="/assets/js/464.037d35a6.js"><link rel="prefetch" href="/assets/js/465.8149292a.js"><link rel="prefetch" href="/assets/js/466.f9f0f937.js"><link rel="prefetch" href="/assets/js/467.f4113a48.js"><link rel="prefetch" href="/assets/js/468.18747025.js"><link rel="prefetch" href="/assets/js/469.b88572d3.js"><link rel="prefetch" href="/assets/js/47.2c60b5b2.js"><link rel="prefetch" href="/assets/js/470.5641e542.js"><link rel="prefetch" href="/assets/js/471.ae0d276c.js"><link rel="prefetch" href="/assets/js/472.1ebbe04c.js"><link rel="prefetch" href="/assets/js/473.8bd95620.js"><link rel="prefetch" href="/assets/js/474.a43755e2.js"><link rel="prefetch" href="/assets/js/475.1e97fd02.js"><link rel="prefetch" href="/assets/js/476.ca714b38.js"><link rel="prefetch" href="/assets/js/477.40d0ba1b.js"><link rel="prefetch" href="/assets/js/478.870b1a14.js"><link rel="prefetch" href="/assets/js/479.88dbb260.js"><link rel="prefetch" href="/assets/js/48.d24599f6.js"><link rel="prefetch" href="/assets/js/480.f3da57b5.js"><link rel="prefetch" href="/assets/js/481.345d6800.js"><link rel="prefetch" href="/assets/js/482.0e0668ff.js"><link rel="prefetch" href="/assets/js/483.0e3bce82.js"><link rel="prefetch" href="/assets/js/484.b90c8dd7.js"><link rel="prefetch" href="/assets/js/485.3ced141b.js"><link rel="prefetch" href="/assets/js/486.1508e319.js"><link rel="prefetch" href="/assets/js/487.2d3eef4c.js"><link rel="prefetch" href="/assets/js/488.49e299f1.js"><link rel="prefetch" href="/assets/js/489.cfd34763.js"><link rel="prefetch" href="/assets/js/49.3de3d3a7.js"><link rel="prefetch" href="/assets/js/490.c305616d.js"><link rel="prefetch" href="/assets/js/491.da9e70ae.js"><link rel="prefetch" href="/assets/js/492.b577d653.js"><link rel="prefetch" href="/assets/js/493.611b89b4.js"><link rel="prefetch" href="/assets/js/494.13c23a99.js"><link rel="prefetch" href="/assets/js/495.c735e3d6.js"><link rel="prefetch" href="/assets/js/496.cd09fba2.js"><link rel="prefetch" href="/assets/js/497.85a8f8f8.js"><link rel="prefetch" href="/assets/js/498.2b430e88.js"><link rel="prefetch" href="/assets/js/499.c1b32b5c.js"><link rel="prefetch" href="/assets/js/5.33db7f08.js"><link rel="prefetch" href="/assets/js/50.27055b53.js"><link rel="prefetch" href="/assets/js/500.3ddf6370.js"><link rel="prefetch" href="/assets/js/501.41eb63d9.js"><link rel="prefetch" href="/assets/js/502.9d85d3d8.js"><link rel="prefetch" href="/assets/js/503.2d92d932.js"><link rel="prefetch" href="/assets/js/504.97aa8eef.js"><link rel="prefetch" href="/assets/js/505.cd9a95e5.js"><link rel="prefetch" href="/assets/js/506.fdd1dcde.js"><link rel="prefetch" href="/assets/js/507.239a1650.js"><link rel="prefetch" href="/assets/js/508.f360fdee.js"><link rel="prefetch" href="/assets/js/509.ee4d3700.js"><link rel="prefetch" href="/assets/js/51.08fc9992.js"><link rel="prefetch" href="/assets/js/510.386facae.js"><link rel="prefetch" href="/assets/js/511.596f52a3.js"><link rel="prefetch" href="/assets/js/512.65dc78dd.js"><link rel="prefetch" href="/assets/js/513.2764dbb1.js"><link rel="prefetch" href="/assets/js/514.d3ea373f.js"><link rel="prefetch" href="/assets/js/515.43dcaa87.js"><link rel="prefetch" href="/assets/js/516.71cffffc.js"><link rel="prefetch" href="/assets/js/517.75d2caec.js"><link rel="prefetch" href="/assets/js/518.69f9e4a4.js"><link rel="prefetch" href="/assets/js/519.803fd46d.js"><link rel="prefetch" href="/assets/js/52.f8b19e2e.js"><link rel="prefetch" href="/assets/js/520.c4253a4c.js"><link rel="prefetch" href="/assets/js/521.d42a7277.js"><link rel="prefetch" href="/assets/js/522.8d30661f.js"><link rel="prefetch" href="/assets/js/523.80a78c0e.js"><link rel="prefetch" href="/assets/js/524.262578ab.js"><link rel="prefetch" href="/assets/js/525.c30e8403.js"><link rel="prefetch" href="/assets/js/53.93b1709a.js"><link rel="prefetch" href="/assets/js/54.23834020.js"><link rel="prefetch" href="/assets/js/55.98bddbab.js"><link rel="prefetch" href="/assets/js/56.57798e09.js"><link rel="prefetch" href="/assets/js/57.6383ab3c.js"><link rel="prefetch" href="/assets/js/58.f93f9595.js"><link rel="prefetch" href="/assets/js/59.6515e2e2.js"><link rel="prefetch" href="/assets/js/6.d37d398a.js"><link rel="prefetch" href="/assets/js/60.5c3fe2a9.js"><link rel="prefetch" href="/assets/js/61.c44ac685.js"><link rel="prefetch" href="/assets/js/62.9b45e8f5.js"><link rel="prefetch" href="/assets/js/63.d2c91b1f.js"><link rel="prefetch" href="/assets/js/64.78c508ed.js"><link rel="prefetch" href="/assets/js/65.88e74e5c.js"><link rel="prefetch" href="/assets/js/66.b3dd78bb.js"><link rel="prefetch" href="/assets/js/67.7e97b055.js"><link rel="prefetch" href="/assets/js/68.7b4dda2f.js"><link rel="prefetch" href="/assets/js/69.23f5fd83.js"><link rel="prefetch" href="/assets/js/7.8c733af6.js"><link rel="prefetch" href="/assets/js/70.dbf8e7b4.js"><link rel="prefetch" href="/assets/js/71.0c9d3b74.js"><link rel="prefetch" href="/assets/js/72.b77a64bb.js"><link rel="prefetch" href="/assets/js/73.72f8ffdb.js"><link rel="prefetch" href="/assets/js/74.1f1823dc.js"><link rel="prefetch" href="/assets/js/75.2f5b0b73.js"><link rel="prefetch" href="/assets/js/76.6a415f61.js"><link rel="prefetch" href="/assets/js/77.2cde9b98.js"><link rel="prefetch" href="/assets/js/78.7d3229e6.js"><link rel="prefetch" href="/assets/js/79.994c527d.js"><link rel="prefetch" href="/assets/js/8.de26e4b6.js"><link rel="prefetch" href="/assets/js/80.82c6c4f9.js"><link rel="prefetch" href="/assets/js/81.336e70e1.js"><link rel="prefetch" href="/assets/js/82.65435ab6.js"><link rel="prefetch" href="/assets/js/83.a6794b4c.js"><link rel="prefetch" href="/assets/js/84.13db35cf.js"><link rel="prefetch" href="/assets/js/85.66678073.js"><link rel="prefetch" href="/assets/js/86.624df956.js"><link rel="prefetch" href="/assets/js/87.c6b315a7.js"><link rel="prefetch" href="/assets/js/88.d61bfb24.js"><link rel="prefetch" href="/assets/js/89.f3c224d1.js"><link rel="prefetch" href="/assets/js/9.fda181fa.js"><link rel="prefetch" href="/assets/js/90.25f57401.js"><link rel="prefetch" href="/assets/js/91.c9cdbdcb.js"><link rel="prefetch" href="/assets/js/92.bf0bf8a0.js"><link rel="prefetch" href="/assets/js/93.13b693fa.js"><link rel="prefetch" href="/assets/js/94.ad6b27ae.js"><link rel="prefetch" href="/assets/js/95.11940531.js"><link rel="prefetch" href="/assets/js/96.05e9812b.js"><link rel="prefetch" href="/assets/js/97.bf5a9c12.js"><link rel="prefetch" href="/assets/js/98.85310a3b.js"><link rel="prefetch" href="/assets/js/99.f1c645af.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.262891fb.js">
     <link rel="stylesheet" href="/assets/css/0.styles.679f71b6.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/Get Started/QuickStart.html" class="nav-link">In progress</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="/zh/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/Operation Manual/DML Data Manipulation Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/Operation Manual/DML Data Manipulation Language.html" class="nav-link">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/Get Started/QuickStart.html" class="nav-link">In progress</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="/zh/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/Operation Manual/DML Data Manipulation Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/Operation Manual/DML Data Manipulation Language.html" class="nav-link">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>开始</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>概述</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>概念</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>服务器端</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>客户端</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading open"><span>操作指南</span> <span class="arrow down"></span></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/zh/UserGuide/Master/Operation Manual/DDL Data Definition Language.html" class="sidebar-link">DDL (数据定义语言)</a></li><li><a href="/zh/UserGuide/Master/Operation Manual/DML Data Manipulation Language.html" class="active sidebar-link">DML (数据操作语言)</a></li><li><a href="/zh/UserGuide/Master/Operation Manual/UDF User Defined Function.html" class="sidebar-link">UDF（用户自定义函数）</a></li><li><a href="/zh/UserGuide/Master/Operation Manual/Administration.html" class="sidebar-link">权限管理语句</a></li><li><a href="/zh/UserGuide/Master/Operation Manual/SQL Reference.html" class="sidebar-link">SQL 参考文档</a></li></ul></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>生态集成</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>系统设计</span> <span class="arrow right"></span></p> <!----></section></li></ul> </aside> <main class="page"> <div class="content content__default"><h1 id="dml-数据操作语言"><a href="#dml-数据操作语言" class="header-anchor">#</a> DML (数据操作语言)</h1> <h2 id="数据接入"><a href="#数据接入" class="header-anchor">#</a> 数据接入</h2> <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/Client/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/Client/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/Operation Manual/SQL Reference.html">INSERT语句</a>节。</p> <h3 id="使用insert语句"><a href="#使用insert语句" class="header-anchor">#</a> 使用INSERT语句</h3> <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><h2 id="数据查询"><a href="#数据查询" class="header-anchor">#</a> 数据查询</h2> <h3 id="时间切片查询"><a href="#时间切片查询" class="header-anchor">#</a> 时间切片查询</h3> <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/Operation Manual/SQL Reference.html">IoTDB SELECT语句</a>。同时，您也可以使用<a href="/zh/UserGuide/Master/Client/Programming - JDBC.html">Java JDBC</a>标准接口来执行相关的查询语句。</p> <h4 id="根据一个时间区间选择一列数据"><a href="#根据一个时间区间选择一列数据" class="header-anchor">#</a> 根据一个时间区间选择一列数据</h4> <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/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><h4 id="根据一个时间区间选择多列数据"><a href="#根据一个时间区间选择多列数据" class="header-anchor">#</a> 根据一个时间区间选择多列数据</h4> <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><h4 id="按照多个时间区间选择同一设备的多列数据"><a href="#按照多个时间区间选择同一设备的多列数据" class="header-anchor">#</a> 按照多个时间区间选择同一设备的多列数据</h4> <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><h4 id="按照多个时间区间选择不同设备的多列数据"><a href="#按照多个时间区间选择不同设备的多列数据" class="header-anchor">#</a> 按照多个时间区间选择不同设备的多列数据</h4> <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="根据时间降序返回"><a href="#根据时间降序返回" class="header-anchor">#</a> 根据时间降序返回</h4> <p>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：</p> <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/Operation Manual/SQL Reference.html">SQL REFERENCE</a>.</p> <h4 id="其他结果返回形式"><a href="#其他结果返回形式" class="header-anchor">#</a> 其他结果返回形式</h4> <p>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'.</p> <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/Operation Manual/SQL Reference.html">SQL REFERENCE</a>。</p> <h3 id="聚合查询"><a href="#聚合查询" class="header-anchor">#</a> 聚合查询</h3> <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> <h4 id="统计总点数"><a href="#统计总点数" class="header-anchor">#</a> 统计总点数</h4> <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="分层聚合查询"><a href="#分层聚合查询" class="header-anchor">#</a> 分层聚合查询</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>假设此时在&quot;root.ln&quot;下面加入名为wf02的子序列，如&quot;root.ln.wf02.wt01.status&quot;。
 需要同时查询&quot;root.ln.wf01&quot;和&quot;root.ln.wf02&quot;下各自status子序列的点个数。则使用查询：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) 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.wf01.*.status)|COUNT(root.ln.wf02.*.status)|
 +----------------------------+----------------------------+
 |                       10080|                       10082|
 +----------------------------+----------------------------+
 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>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> <h3 id="降频聚合查询"><a href="#降频聚合查询" class="header-anchor">#</a> 降频聚合查询</h3> <p>本章节主要介绍降频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/Operation Manual/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图5.2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> <center><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;">
 **图 5.2 三类参数的实际含义**</center> <h4 id="未指定滑动步长的降频聚合查询"><a href="#未指定滑动步长的降频聚合查询" class="header-anchor">#</a> 未指定滑动步长的降频聚合查询</h4> <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><h4 id="指定滑动步长的降频聚合查询"><a href="#指定滑动步长的降频聚合查询" class="header-anchor">#</a> 指定滑动步长的降频聚合查询</h4> <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><h4 id="带值过滤条件的降频聚合查询"><a href="#带值过滤条件的降频聚合查询" class="header-anchor">#</a> 带值过滤条件的降频聚合查询</h4> <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), 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|                            179|                                   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 0.018s
 </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></div></div><h4 id="按照自然月份的降频聚合查询"><a href="#按照自然月份的降频聚合查询" class="header-anchor">#</a> 按照自然月份的降频聚合查询</h4> <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>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2029-11-07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><h4 id="左开右闭区间"><a href="#左开右闭区间" class="header-anchor">#</a> 左开右闭区间</h4> <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5的数据，但是会包含时间点40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="降采样后按level聚合查询"><a href="#降采样后按level聚合查询" class="header-anchor">#</a> 降采样后按Level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="降频聚合查询补空值"><a href="#降频聚合查询补空值" class="header-anchor">#</a> 降频聚合查询补空值</h4> <p>降频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> <h5 id="previous-和-previousuntillast-的区别"><a href="#previous-和-previousuntillast-的区别" class="header-anchor">#</a> PREVIOUS 和 PREVIOUSUNTILLAST 的区别</h5> <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> <h3 id="最新数据查询"><a href="#最新数据查询" class="header-anchor">#</a> 最新数据查询</h3> <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 | Path | Value |
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</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><h3 id="自动填充"><a href="#自动填充" class="header-anchor">#</a> 自动填充</h3> <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> <h4 id="填充功能"><a href="#填充功能" class="header-anchor">#</a> 填充功能</h4> <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><h4 id="数据类型和填充方法之间的对应关系"><a href="#数据类型和填充方法之间的对应关系" class="header-anchor">#</a> 数据类型和填充方法之间的对应关系</h4> <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> <p>如果未指定fill方法，则每种数据类型均具有其自己的默认fill方法和参数。 对应关系如表3-7所示。</p> <center>**表3-7各种数据类型的默认填充方法和参数**
 <table><thead><tr><th style="text-align:left;">数据类型</th> <th style="text-align:left;">默认填充方法和参数</th></tr></thead> <tbody><tr><td style="text-align:left;">boolean</td> <td style="text-align:left;">previous, 600000</td></tr> <tr><td style="text-align:left;">int32</td> <td style="text-align:left;">linear, 600000, 600000</td></tr> <tr><td style="text-align:left;">int64</td> <td style="text-align:left;">linear, 600000, 600000</td></tr> <tr><td style="text-align:left;">float</td> <td style="text-align:left;">linear, 600000, 600000</td></tr> <tr><td style="text-align:left;">double</td> <td style="text-align:left;">linear, 600000, 600000</td></tr> <tr><td style="text-align:left;">text</td> <td style="text-align:left;">previous, 600000</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> <h3 id="对查询结果的行和列控制"><a href="#对查询结果的行和列控制" class="header-anchor">#</a> 对查询结果的行和列控制</h3> <p>IoTDB提供 <a href="/zh/UserGuide/Master/Operation Manual/SQL Reference.html">LIMIT/SLIMIT</a> 子句和 <a href="/zh/UserGuide/Master/Operation Manual/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/Client/Programming - JDBC.html">Java JDBC</a> 标准接口执行查询。</p> <h4 id="查询结果的行控制"><a href="#查询结果的行控制" class="header-anchor">#</a> 查询结果的行控制</h4> <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 2 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 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>SQL语句子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|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: line 1:107 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><h4 id="查询结果的列控制"><a href="#查询结果的列控制" class="header-anchor">#</a> 查询结果的列控制</h4> <p>通过使用LIMIT和OFFSET子句，用户可以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OFFSET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一列，即电源状态。 SQL语句要求在“ 2017-11-01T00：05：00.000”和“ 2017-11-01T00：12：00.000”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.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 * 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二列，即温度。 SQL语句要求在“ 2017-11-01T00：05：00.000”和“ 2017-11-01T00：12：00.000”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.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>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。</p> <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><h4 id="控制查询结果的行和列"><a href="#控制查询结果的行和列" class="header-anchor">#</a> 控制查询结果的行和列</h4> <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><h3 id="使用别名"><a href="#使用别名" class="header-anchor">#</a> 使用别名</h3> <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="其他结果集格式"><a href="#其他结果集格式" class="header-anchor">#</a> 其他结果集格式</h4> <p>此外，IoTDB支持两种其他结果集格式：“按设备对齐”和“禁用对齐”。</p> <p>“按设备对齐”指示将deviceId视为一列。 因此，数据集中的列完全有限。</p> <p>SQL语句是：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select s1,s2 from root.sg1.* ALIGN BY DEVICE

 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>结果显示如下:</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>“禁用对齐”指示结果集中每个时间序列都有3列。</p> <p>SQL语句是:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select * from root.sg1 where time &gt; 10 disable align
 </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>结果显示如下:</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>有关更多语法描述，更多语法请参照 <a href="/zh/UserGuide/Master/Operation Manual/SQL Reference.html">SQL REFERENCE</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><p>当SLIMIT子句的参数SOFFSET不小于可用时间序列数时，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 * 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 2

 </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> <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/Operation Manual/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/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><h2 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)</h2> <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/Operation Manual/DDL Data Definition Language.html" class="prev">
           DDL (数据定义语言)
         </a></span> <span class="next"><a href="/zh/UserGuide/Master/Operation Manual/UDF User Defined Function.html">
           UDF（用户自定义函数）
         </a>
         →
       </span></p></div> <p style="text-align: center;">Copyright © 2020 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.a12b5307.js" defer></script><script src="/assets/js/3.49f0f20a.js" defer></script><script src="/assets/js/341.626acd05.js" defer></script>
   </body>
 </html>