blob: f90e796a588099d6ea87677b9c3865fb9778f7d5 [file] [log] [blame]
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title> </title>
<meta name="generator" content="VuePress 1.8.2">
<link rel="icon" href="/favicon.ico">
<meta name="description" content=" ">
<meta name="Description" content="Apache IoTDB: Time Series Database for IoT">
<meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据">
<meta name="baidu-site-verification" content="wfKETzB3OT">
<meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo">
<link rel="preload" href="/assets/css/0.styles.70ddaee8.css" as="style"><link rel="preload" href="/assets/js/app.008afd2b.js" as="script"><link rel="preload" href="/assets/js/3.9588d9cb.js" as="script"><link rel="preload" href="/assets/js/4.e8b2d372.js" as="script"><link rel="preload" href="/assets/js/500.c468af94.js" as="script"><link rel="prefetch" href="/assets/js/10.6c6eacc5.js"><link rel="prefetch" href="/assets/js/100.f441a843.js"><link rel="prefetch" href="/assets/js/101.aa202896.js"><link rel="prefetch" href="/assets/js/102.8c46dd84.js"><link rel="prefetch" href="/assets/js/103.afee4ee6.js"><link rel="prefetch" href="/assets/js/104.5a5ca5b6.js"><link rel="prefetch" href="/assets/js/105.004523e3.js"><link rel="prefetch" href="/assets/js/106.6858346e.js"><link rel="prefetch" href="/assets/js/107.9c6775de.js"><link rel="prefetch" href="/assets/js/108.8e6758cc.js"><link rel="prefetch" href="/assets/js/109.22ddfff4.js"><link rel="prefetch" href="/assets/js/11.e6c21699.js"><link rel="prefetch" href="/assets/js/110.4aa186e9.js"><link rel="prefetch" href="/assets/js/111.234d040b.js"><link rel="prefetch" href="/assets/js/112.9a0945d1.js"><link rel="prefetch" href="/assets/js/113.98d95448.js"><link rel="prefetch" href="/assets/js/114.3e61b476.js"><link rel="prefetch" href="/assets/js/115.f7a2c654.js"><link rel="prefetch" href="/assets/js/116.9f43ac05.js"><link rel="prefetch" href="/assets/js/117.5efe3aa6.js"><link rel="prefetch" href="/assets/js/118.28f3de60.js"><link rel="prefetch" href="/assets/js/119.8e94619b.js"><link rel="prefetch" href="/assets/js/12.14f0b661.js"><link rel="prefetch" href="/assets/js/120.f43bbd29.js"><link rel="prefetch" href="/assets/js/121.01fc5c3d.js"><link rel="prefetch" href="/assets/js/122.7dee742a.js"><link rel="prefetch" href="/assets/js/123.b735576f.js"><link rel="prefetch" href="/assets/js/124.11767877.js"><link rel="prefetch" href="/assets/js/125.ba652ed9.js"><link rel="prefetch" href="/assets/js/126.e072d06b.js"><link rel="prefetch" href="/assets/js/127.2b69b348.js"><link rel="prefetch" href="/assets/js/128.0010ef81.js"><link rel="prefetch" href="/assets/js/129.66a40322.js"><link rel="prefetch" href="/assets/js/13.16053ad6.js"><link rel="prefetch" href="/assets/js/130.01d25148.js"><link rel="prefetch" href="/assets/js/131.298041b8.js"><link rel="prefetch" href="/assets/js/132.789ffdf5.js"><link rel="prefetch" href="/assets/js/133.46fe7610.js"><link rel="prefetch" href="/assets/js/134.528d156d.js"><link rel="prefetch" href="/assets/js/135.fb783ddd.js"><link rel="prefetch" href="/assets/js/136.5e574da6.js"><link rel="prefetch" href="/assets/js/137.265ac5ad.js"><link rel="prefetch" href="/assets/js/138.e4397630.js"><link rel="prefetch" href="/assets/js/139.97a4d294.js"><link rel="prefetch" href="/assets/js/14.d90e5a91.js"><link rel="prefetch" href="/assets/js/140.b08e2fe4.js"><link rel="prefetch" href="/assets/js/141.5d84ecd2.js"><link rel="prefetch" href="/assets/js/142.1ed64560.js"><link rel="prefetch" href="/assets/js/143.67702842.js"><link rel="prefetch" href="/assets/js/144.50de381a.js"><link rel="prefetch" href="/assets/js/145.0e1664c6.js"><link rel="prefetch" href="/assets/js/146.a9acdfd4.js"><link rel="prefetch" href="/assets/js/147.2dced5b8.js"><link rel="prefetch" href="/assets/js/148.4907a26b.js"><link rel="prefetch" href="/assets/js/149.cf0a0146.js"><link rel="prefetch" href="/assets/js/15.b8d48dd6.js"><link rel="prefetch" href="/assets/js/150.1a4c26ef.js"><link rel="prefetch" href="/assets/js/151.2597998d.js"><link rel="prefetch" href="/assets/js/152.782f5a69.js"><link rel="prefetch" href="/assets/js/153.e3039e67.js"><link rel="prefetch" href="/assets/js/154.8a72c3fd.js"><link rel="prefetch" href="/assets/js/155.36bf8e12.js"><link rel="prefetch" href="/assets/js/156.bd9d2588.js"><link rel="prefetch" href="/assets/js/157.b466d500.js"><link rel="prefetch" href="/assets/js/158.4b5b9b2c.js"><link rel="prefetch" href="/assets/js/159.d54a65ac.js"><link rel="prefetch" href="/assets/js/16.5367af24.js"><link rel="prefetch" href="/assets/js/160.c9a3f8db.js"><link rel="prefetch" href="/assets/js/161.bd39ae43.js"><link rel="prefetch" href="/assets/js/162.fef5ee6d.js"><link rel="prefetch" href="/assets/js/163.bc31c077.js"><link rel="prefetch" href="/assets/js/164.a928aacf.js"><link rel="prefetch" href="/assets/js/165.e0b76fc0.js"><link rel="prefetch" href="/assets/js/166.a321cdcf.js"><link rel="prefetch" href="/assets/js/167.d5d31bce.js"><link rel="prefetch" href="/assets/js/168.56ce8edc.js"><link rel="prefetch" href="/assets/js/169.c8d13d84.js"><link rel="prefetch" href="/assets/js/17.55647d0c.js"><link rel="prefetch" href="/assets/js/170.0d51d2a4.js"><link rel="prefetch" href="/assets/js/171.39b901b1.js"><link rel="prefetch" href="/assets/js/172.09b15c00.js"><link rel="prefetch" href="/assets/js/173.195bb10b.js"><link rel="prefetch" href="/assets/js/174.86d00222.js"><link rel="prefetch" href="/assets/js/175.bb79f07a.js"><link rel="prefetch" href="/assets/js/176.1bea4827.js"><link rel="prefetch" href="/assets/js/177.81e6e716.js"><link rel="prefetch" href="/assets/js/178.1665f163.js"><link rel="prefetch" href="/assets/js/179.4969a9b4.js"><link rel="prefetch" href="/assets/js/18.01351113.js"><link rel="prefetch" href="/assets/js/180.b38bc3b4.js"><link rel="prefetch" href="/assets/js/181.b34911ce.js"><link rel="prefetch" href="/assets/js/182.a9450a93.js"><link rel="prefetch" href="/assets/js/183.205c4253.js"><link rel="prefetch" href="/assets/js/184.620e037b.js"><link rel="prefetch" href="/assets/js/185.1ea89551.js"><link rel="prefetch" href="/assets/js/186.d7de045a.js"><link rel="prefetch" href="/assets/js/187.5a87087f.js"><link rel="prefetch" href="/assets/js/188.fc7f1ec5.js"><link rel="prefetch" href="/assets/js/189.51368dc6.js"><link rel="prefetch" href="/assets/js/19.1cd96417.js"><link rel="prefetch" href="/assets/js/190.2cae301e.js"><link rel="prefetch" href="/assets/js/191.efae811f.js"><link rel="prefetch" href="/assets/js/192.8c2ffd41.js"><link rel="prefetch" href="/assets/js/193.ece6d8e6.js"><link rel="prefetch" href="/assets/js/194.30699357.js"><link rel="prefetch" href="/assets/js/195.b554d3a1.js"><link rel="prefetch" href="/assets/js/196.6b8320b8.js"><link rel="prefetch" href="/assets/js/197.1323722a.js"><link rel="prefetch" href="/assets/js/198.f89da54a.js"><link rel="prefetch" href="/assets/js/199.2d2fe9c7.js"><link rel="prefetch" href="/assets/js/20.9bdb2486.js"><link rel="prefetch" href="/assets/js/200.b4ba119c.js"><link rel="prefetch" href="/assets/js/201.cd34c71a.js"><link rel="prefetch" href="/assets/js/202.8236f88e.js"><link rel="prefetch" href="/assets/js/203.59de571c.js"><link rel="prefetch" href="/assets/js/204.c9127294.js"><link rel="prefetch" href="/assets/js/205.2eb75651.js"><link rel="prefetch" href="/assets/js/206.ecefb9be.js"><link rel="prefetch" href="/assets/js/207.b22ddfcc.js"><link rel="prefetch" href="/assets/js/208.7fed56ff.js"><link rel="prefetch" href="/assets/js/209.c75165f6.js"><link rel="prefetch" href="/assets/js/21.aa4d4a0a.js"><link rel="prefetch" href="/assets/js/210.10104abd.js"><link rel="prefetch" href="/assets/js/211.a4917ce1.js"><link rel="prefetch" href="/assets/js/212.eaff6831.js"><link rel="prefetch" href="/assets/js/213.1c7b9c77.js"><link rel="prefetch" href="/assets/js/214.8bfe7d76.js"><link rel="prefetch" href="/assets/js/215.cd2cbb91.js"><link rel="prefetch" href="/assets/js/216.6a22b694.js"><link rel="prefetch" href="/assets/js/217.b5aec962.js"><link rel="prefetch" href="/assets/js/218.5c59ae7e.js"><link rel="prefetch" href="/assets/js/219.6ad3896b.js"><link rel="prefetch" href="/assets/js/22.3accf996.js"><link rel="prefetch" href="/assets/js/220.9343fb9c.js"><link rel="prefetch" href="/assets/js/221.486867a4.js"><link rel="prefetch" href="/assets/js/222.23993077.js"><link rel="prefetch" href="/assets/js/223.a4a46a86.js"><link rel="prefetch" href="/assets/js/224.77d2ff20.js"><link rel="prefetch" href="/assets/js/225.e3a3ada3.js"><link rel="prefetch" href="/assets/js/226.af6007aa.js"><link rel="prefetch" href="/assets/js/227.90babe59.js"><link rel="prefetch" href="/assets/js/228.44b23515.js"><link rel="prefetch" href="/assets/js/229.7a6000e9.js"><link rel="prefetch" href="/assets/js/23.efe0953a.js"><link rel="prefetch" href="/assets/js/230.079de91e.js"><link rel="prefetch" href="/assets/js/231.4a6e8727.js"><link rel="prefetch" href="/assets/js/232.a8f59928.js"><link rel="prefetch" href="/assets/js/233.db0e2cae.js"><link rel="prefetch" href="/assets/js/234.70674a90.js"><link rel="prefetch" href="/assets/js/235.05a1467f.js"><link rel="prefetch" href="/assets/js/236.b91843fa.js"><link rel="prefetch" href="/assets/js/237.2aa66902.js"><link rel="prefetch" href="/assets/js/238.5d234f1c.js"><link rel="prefetch" href="/assets/js/239.cd89238f.js"><link rel="prefetch" href="/assets/js/24.b43efcd3.js"><link rel="prefetch" href="/assets/js/240.c6970034.js"><link rel="prefetch" href="/assets/js/241.d9b26ec3.js"><link rel="prefetch" href="/assets/js/242.eb26b6e0.js"><link rel="prefetch" href="/assets/js/243.07274c1c.js"><link rel="prefetch" href="/assets/js/244.dab8212d.js"><link rel="prefetch" href="/assets/js/245.ed899b23.js"><link rel="prefetch" href="/assets/js/246.e611d615.js"><link rel="prefetch" href="/assets/js/247.9564078b.js"><link rel="prefetch" href="/assets/js/248.7c3302f2.js"><link rel="prefetch" href="/assets/js/249.783af8be.js"><link rel="prefetch" href="/assets/js/25.f560c37a.js"><link rel="prefetch" href="/assets/js/250.b5cbb227.js"><link rel="prefetch" href="/assets/js/251.f655cbdc.js"><link rel="prefetch" href="/assets/js/252.aac367b9.js"><link rel="prefetch" href="/assets/js/253.b9b0b1ec.js"><link rel="prefetch" href="/assets/js/254.3fff7636.js"><link rel="prefetch" href="/assets/js/255.883d4534.js"><link rel="prefetch" href="/assets/js/256.55a847da.js"><link rel="prefetch" href="/assets/js/257.1930d277.js"><link rel="prefetch" href="/assets/js/258.74c88892.js"><link rel="prefetch" href="/assets/js/259.78dc1d3d.js"><link rel="prefetch" href="/assets/js/26.960d4740.js"><link rel="prefetch" href="/assets/js/260.8831bed0.js"><link rel="prefetch" href="/assets/js/261.984c8766.js"><link rel="prefetch" href="/assets/js/262.c1fd14a3.js"><link rel="prefetch" href="/assets/js/263.b1b29b3f.js"><link rel="prefetch" href="/assets/js/264.56ac69bd.js"><link rel="prefetch" href="/assets/js/265.b1209eed.js"><link rel="prefetch" href="/assets/js/266.04b3660b.js"><link rel="prefetch" href="/assets/js/267.a18f8dea.js"><link rel="prefetch" href="/assets/js/268.4fdcfd84.js"><link rel="prefetch" href="/assets/js/269.ed7fa6a2.js"><link rel="prefetch" href="/assets/js/27.2afb2f7e.js"><link rel="prefetch" href="/assets/js/270.05bbeaf2.js"><link rel="prefetch" href="/assets/js/271.9b8413f7.js"><link rel="prefetch" href="/assets/js/272.da5b1138.js"><link rel="prefetch" href="/assets/js/273.d9c16fd3.js"><link rel="prefetch" href="/assets/js/274.25e2d4aa.js"><link rel="prefetch" href="/assets/js/275.1769ecfe.js"><link rel="prefetch" href="/assets/js/276.662d0d9a.js"><link rel="prefetch" href="/assets/js/277.7a0477ad.js"><link rel="prefetch" href="/assets/js/278.3c371564.js"><link rel="prefetch" href="/assets/js/279.74e285a6.js"><link rel="prefetch" href="/assets/js/28.502a4713.js"><link rel="prefetch" href="/assets/js/280.80655b6d.js"><link rel="prefetch" href="/assets/js/281.055809d5.js"><link rel="prefetch" href="/assets/js/282.ef8ed3a4.js"><link rel="prefetch" href="/assets/js/283.68d97af6.js"><link rel="prefetch" href="/assets/js/284.875352c6.js"><link rel="prefetch" href="/assets/js/285.ba22a0c4.js"><link rel="prefetch" href="/assets/js/286.e5ae3146.js"><link rel="prefetch" href="/assets/js/287.ed045936.js"><link rel="prefetch" href="/assets/js/288.fe29b6ba.js"><link rel="prefetch" href="/assets/js/289.c563154f.js"><link rel="prefetch" href="/assets/js/29.430f946b.js"><link rel="prefetch" href="/assets/js/290.8ad6ee0b.js"><link rel="prefetch" href="/assets/js/291.471bac2d.js"><link rel="prefetch" href="/assets/js/292.1c33e254.js"><link rel="prefetch" href="/assets/js/293.6b4f21d8.js"><link rel="prefetch" href="/assets/js/294.1f595d4e.js"><link rel="prefetch" href="/assets/js/295.38dc8999.js"><link rel="prefetch" href="/assets/js/296.8ee8330c.js"><link rel="prefetch" href="/assets/js/297.c8beeb64.js"><link rel="prefetch" href="/assets/js/298.a3900676.js"><link rel="prefetch" href="/assets/js/299.20584d52.js"><link rel="prefetch" href="/assets/js/30.c3589f5c.js"><link rel="prefetch" href="/assets/js/300.0a9310e3.js"><link rel="prefetch" href="/assets/js/301.c19b0d75.js"><link rel="prefetch" href="/assets/js/302.2d7ad9d4.js"><link rel="prefetch" href="/assets/js/303.5f2f214c.js"><link rel="prefetch" href="/assets/js/304.e40203bf.js"><link rel="prefetch" href="/assets/js/305.4cc015a0.js"><link rel="prefetch" href="/assets/js/306.6d7a484b.js"><link rel="prefetch" href="/assets/js/307.8fabf975.js"><link rel="prefetch" href="/assets/js/308.172e54ab.js"><link rel="prefetch" href="/assets/js/309.65f423bc.js"><link rel="prefetch" href="/assets/js/31.abfdfce0.js"><link rel="prefetch" href="/assets/js/310.225538d2.js"><link rel="prefetch" href="/assets/js/311.bb45bea9.js"><link rel="prefetch" href="/assets/js/312.93467b61.js"><link rel="prefetch" href="/assets/js/313.c834a0a9.js"><link rel="prefetch" href="/assets/js/314.5c73a0fc.js"><link rel="prefetch" href="/assets/js/315.aa61b285.js"><link rel="prefetch" href="/assets/js/316.cfb69d4b.js"><link rel="prefetch" href="/assets/js/317.da4a91b0.js"><link rel="prefetch" href="/assets/js/318.46efc088.js"><link rel="prefetch" href="/assets/js/319.79a440dc.js"><link rel="prefetch" href="/assets/js/32.386fc03f.js"><link rel="prefetch" href="/assets/js/320.97969063.js"><link rel="prefetch" href="/assets/js/321.dcea850e.js"><link rel="prefetch" href="/assets/js/322.85e35a08.js"><link rel="prefetch" href="/assets/js/323.65abc480.js"><link rel="prefetch" href="/assets/js/324.d8784c8c.js"><link rel="prefetch" href="/assets/js/325.e6297c5d.js"><link rel="prefetch" href="/assets/js/326.e8fc9af6.js"><link rel="prefetch" href="/assets/js/327.7f26d880.js"><link rel="prefetch" href="/assets/js/328.8de33749.js"><link rel="prefetch" href="/assets/js/329.9f5c58bc.js"><link rel="prefetch" href="/assets/js/33.746055ec.js"><link rel="prefetch" href="/assets/js/330.baddad1f.js"><link rel="prefetch" href="/assets/js/331.5dbc5e59.js"><link rel="prefetch" href="/assets/js/332.1bc0077c.js"><link rel="prefetch" href="/assets/js/333.7d957d5c.js"><link rel="prefetch" href="/assets/js/334.e904343d.js"><link rel="prefetch" href="/assets/js/335.24025f5d.js"><link rel="prefetch" href="/assets/js/336.992773e5.js"><link rel="prefetch" href="/assets/js/337.cf494c2e.js"><link rel="prefetch" href="/assets/js/338.ab7046f1.js"><link rel="prefetch" href="/assets/js/339.1b438c89.js"><link rel="prefetch" href="/assets/js/34.fec188a0.js"><link rel="prefetch" href="/assets/js/340.5d928b52.js"><link rel="prefetch" href="/assets/js/341.99069ef1.js"><link rel="prefetch" href="/assets/js/342.d0773404.js"><link rel="prefetch" href="/assets/js/343.e8fa7c2c.js"><link rel="prefetch" href="/assets/js/344.6dbd005f.js"><link rel="prefetch" href="/assets/js/345.eb42ce07.js"><link rel="prefetch" href="/assets/js/346.d9ffa6c8.js"><link rel="prefetch" href="/assets/js/347.5a84f5c0.js"><link rel="prefetch" href="/assets/js/348.22711fba.js"><link rel="prefetch" href="/assets/js/349.afcf98c3.js"><link rel="prefetch" href="/assets/js/35.9e5d9ace.js"><link rel="prefetch" href="/assets/js/350.b0f0f8d2.js"><link rel="prefetch" href="/assets/js/351.bc23683d.js"><link rel="prefetch" href="/assets/js/352.bdf30083.js"><link rel="prefetch" href="/assets/js/353.2ee09980.js"><link rel="prefetch" href="/assets/js/354.c2d41bcd.js"><link rel="prefetch" href="/assets/js/355.80d868e9.js"><link rel="prefetch" href="/assets/js/356.991d5d38.js"><link rel="prefetch" href="/assets/js/357.fe667185.js"><link rel="prefetch" href="/assets/js/358.8dc45914.js"><link rel="prefetch" href="/assets/js/359.e4034b22.js"><link rel="prefetch" href="/assets/js/36.fbd54d31.js"><link rel="prefetch" href="/assets/js/360.0042b7b2.js"><link rel="prefetch" href="/assets/js/361.3db264f5.js"><link rel="prefetch" href="/assets/js/362.fbca8447.js"><link rel="prefetch" href="/assets/js/363.d0d79de2.js"><link rel="prefetch" href="/assets/js/364.28ce47cc.js"><link rel="prefetch" href="/assets/js/365.2b03e7be.js"><link rel="prefetch" href="/assets/js/366.432cfc2e.js"><link rel="prefetch" href="/assets/js/367.06376298.js"><link rel="prefetch" href="/assets/js/368.d0f36b61.js"><link rel="prefetch" href="/assets/js/369.1eb544c0.js"><link rel="prefetch" href="/assets/js/37.c842407e.js"><link rel="prefetch" href="/assets/js/370.03356f65.js"><link rel="prefetch" href="/assets/js/371.04a4973b.js"><link rel="prefetch" href="/assets/js/372.081f8d14.js"><link rel="prefetch" href="/assets/js/373.0fa39c02.js"><link rel="prefetch" href="/assets/js/374.90b06857.js"><link rel="prefetch" href="/assets/js/375.29258717.js"><link rel="prefetch" href="/assets/js/376.34bd82c1.js"><link rel="prefetch" href="/assets/js/377.ac0c706b.js"><link rel="prefetch" href="/assets/js/378.ab5a0147.js"><link rel="prefetch" href="/assets/js/379.31920e16.js"><link rel="prefetch" href="/assets/js/38.e4d7106a.js"><link rel="prefetch" href="/assets/js/380.f64a819b.js"><link rel="prefetch" href="/assets/js/381.5eece063.js"><link rel="prefetch" href="/assets/js/382.8b618505.js"><link rel="prefetch" href="/assets/js/383.2bf7f26e.js"><link rel="prefetch" href="/assets/js/384.5151f4c9.js"><link rel="prefetch" href="/assets/js/385.44fcceaf.js"><link rel="prefetch" href="/assets/js/386.dc242726.js"><link rel="prefetch" href="/assets/js/387.edc52f87.js"><link rel="prefetch" href="/assets/js/388.ff0a1a30.js"><link rel="prefetch" href="/assets/js/389.41e7a717.js"><link rel="prefetch" href="/assets/js/39.1728ceb9.js"><link rel="prefetch" href="/assets/js/390.8b42f3d8.js"><link rel="prefetch" href="/assets/js/391.c801e439.js"><link rel="prefetch" href="/assets/js/392.8bf00061.js"><link rel="prefetch" href="/assets/js/393.163638af.js"><link rel="prefetch" href="/assets/js/394.cc0618bd.js"><link rel="prefetch" href="/assets/js/395.2098476d.js"><link rel="prefetch" href="/assets/js/396.4165d515.js"><link rel="prefetch" href="/assets/js/397.b037470f.js"><link rel="prefetch" href="/assets/js/398.abc5fb71.js"><link rel="prefetch" href="/assets/js/399.641aea15.js"><link rel="prefetch" href="/assets/js/40.1f714478.js"><link rel="prefetch" href="/assets/js/400.3a4f7fd2.js"><link rel="prefetch" href="/assets/js/401.b3b7898b.js"><link rel="prefetch" href="/assets/js/402.82371bd8.js"><link rel="prefetch" href="/assets/js/403.c1fdf3cf.js"><link rel="prefetch" href="/assets/js/404.abf86e73.js"><link rel="prefetch" href="/assets/js/405.676dc510.js"><link rel="prefetch" href="/assets/js/406.8dd08605.js"><link rel="prefetch" href="/assets/js/407.280c26bf.js"><link rel="prefetch" href="/assets/js/408.72fb9e09.js"><link rel="prefetch" href="/assets/js/409.74678ce5.js"><link rel="prefetch" href="/assets/js/41.a0cd1611.js"><link rel="prefetch" href="/assets/js/410.36451a8c.js"><link rel="prefetch" href="/assets/js/411.f1ff4c0b.js"><link rel="prefetch" href="/assets/js/412.04301146.js"><link rel="prefetch" href="/assets/js/413.7da0ddb5.js"><link rel="prefetch" href="/assets/js/414.cb66a127.js"><link rel="prefetch" href="/assets/js/415.7744233a.js"><link rel="prefetch" href="/assets/js/416.05894549.js"><link rel="prefetch" href="/assets/js/417.1384fa1d.js"><link rel="prefetch" href="/assets/js/418.132c85d3.js"><link rel="prefetch" href="/assets/js/419.b99fedce.js"><link rel="prefetch" href="/assets/js/42.bc2cc534.js"><link rel="prefetch" href="/assets/js/420.3b2ecdf9.js"><link rel="prefetch" href="/assets/js/421.6b6e5b7c.js"><link rel="prefetch" href="/assets/js/422.3d1cdf86.js"><link rel="prefetch" href="/assets/js/423.ce7a67ed.js"><link rel="prefetch" href="/assets/js/424.1d05b57e.js"><link rel="prefetch" href="/assets/js/425.ded84cc6.js"><link rel="prefetch" href="/assets/js/426.ab410a61.js"><link rel="prefetch" href="/assets/js/427.79d49688.js"><link rel="prefetch" href="/assets/js/428.cc2250df.js"><link rel="prefetch" href="/assets/js/429.e4cc6d05.js"><link rel="prefetch" href="/assets/js/43.530ad2c0.js"><link rel="prefetch" href="/assets/js/430.d16e8a96.js"><link rel="prefetch" href="/assets/js/431.990f85af.js"><link rel="prefetch" href="/assets/js/432.859a5d66.js"><link rel="prefetch" href="/assets/js/433.8c498fa0.js"><link rel="prefetch" href="/assets/js/434.53147302.js"><link rel="prefetch" href="/assets/js/435.58330cd8.js"><link rel="prefetch" href="/assets/js/436.c8f1e86a.js"><link rel="prefetch" href="/assets/js/437.a55f4dbb.js"><link rel="prefetch" href="/assets/js/438.dcca94d4.js"><link rel="prefetch" href="/assets/js/439.4800bff6.js"><link rel="prefetch" href="/assets/js/44.6eb96ab9.js"><link rel="prefetch" href="/assets/js/440.1915866f.js"><link rel="prefetch" href="/assets/js/441.3c96e250.js"><link rel="prefetch" href="/assets/js/442.1e6b75e6.js"><link rel="prefetch" href="/assets/js/443.d84fe66d.js"><link rel="prefetch" href="/assets/js/444.385ac6fc.js"><link rel="prefetch" href="/assets/js/445.9774645e.js"><link rel="prefetch" href="/assets/js/446.b78ddb1c.js"><link rel="prefetch" href="/assets/js/447.7114c40d.js"><link rel="prefetch" href="/assets/js/448.7e4bdd00.js"><link rel="prefetch" href="/assets/js/449.a6eeb6ae.js"><link rel="prefetch" href="/assets/js/45.c644dd5d.js"><link rel="prefetch" href="/assets/js/450.f9f5f0d0.js"><link rel="prefetch" href="/assets/js/451.83d9812a.js"><link rel="prefetch" href="/assets/js/452.a577afb6.js"><link rel="prefetch" href="/assets/js/453.15b6bbf0.js"><link rel="prefetch" href="/assets/js/454.06f246f5.js"><link rel="prefetch" href="/assets/js/455.8d2ad90c.js"><link rel="prefetch" href="/assets/js/456.a227f6d7.js"><link rel="prefetch" href="/assets/js/457.95a49083.js"><link rel="prefetch" href="/assets/js/458.36ff96e1.js"><link rel="prefetch" href="/assets/js/459.3b6f40b5.js"><link rel="prefetch" href="/assets/js/46.448953fb.js"><link rel="prefetch" href="/assets/js/460.be1869a0.js"><link rel="prefetch" href="/assets/js/461.51b9222a.js"><link rel="prefetch" href="/assets/js/462.df0c221a.js"><link rel="prefetch" href="/assets/js/463.9a371857.js"><link rel="prefetch" href="/assets/js/464.7ec4034f.js"><link rel="prefetch" href="/assets/js/465.a0491896.js"><link rel="prefetch" href="/assets/js/466.a0de32c6.js"><link rel="prefetch" href="/assets/js/467.1ac4b480.js"><link rel="prefetch" href="/assets/js/468.0a58d403.js"><link rel="prefetch" href="/assets/js/469.84b3d4a8.js"><link rel="prefetch" href="/assets/js/47.7c84631d.js"><link rel="prefetch" href="/assets/js/470.3c60b840.js"><link rel="prefetch" href="/assets/js/471.a014a7c1.js"><link rel="prefetch" href="/assets/js/472.e7107400.js"><link rel="prefetch" href="/assets/js/473.90194636.js"><link rel="prefetch" href="/assets/js/474.87c67d9d.js"><link rel="prefetch" href="/assets/js/475.f03e9a58.js"><link rel="prefetch" href="/assets/js/476.ccf0689f.js"><link rel="prefetch" href="/assets/js/477.f14c4e2e.js"><link rel="prefetch" href="/assets/js/478.1cb7888a.js"><link rel="prefetch" href="/assets/js/479.dbb363cc.js"><link rel="prefetch" href="/assets/js/48.9c982d00.js"><link rel="prefetch" href="/assets/js/480.3ae635a0.js"><link rel="prefetch" href="/assets/js/481.02c66634.js"><link rel="prefetch" href="/assets/js/482.f5522d63.js"><link rel="prefetch" href="/assets/js/483.e69e0752.js"><link rel="prefetch" href="/assets/js/484.4444d4c3.js"><link rel="prefetch" href="/assets/js/485.50a9bc60.js"><link rel="prefetch" href="/assets/js/486.3479a06a.js"><link rel="prefetch" href="/assets/js/487.77df985e.js"><link rel="prefetch" href="/assets/js/488.374fddc3.js"><link rel="prefetch" href="/assets/js/489.6093a2b1.js"><link rel="prefetch" href="/assets/js/49.d1bb78f2.js"><link rel="prefetch" href="/assets/js/490.7d191173.js"><link rel="prefetch" href="/assets/js/491.26ef2270.js"><link rel="prefetch" href="/assets/js/492.80ec6fe3.js"><link rel="prefetch" href="/assets/js/493.20c546bf.js"><link rel="prefetch" href="/assets/js/494.a8de7e2b.js"><link rel="prefetch" href="/assets/js/495.9aa31267.js"><link rel="prefetch" href="/assets/js/496.88a80b7a.js"><link rel="prefetch" href="/assets/js/497.00173ce0.js"><link rel="prefetch" href="/assets/js/498.f7663f02.js"><link rel="prefetch" href="/assets/js/499.6e49c57d.js"><link rel="prefetch" href="/assets/js/5.3c940b3a.js"><link rel="prefetch" href="/assets/js/50.3bc020e8.js"><link rel="prefetch" href="/assets/js/501.9e6a042c.js"><link rel="prefetch" href="/assets/js/502.f56ca8f8.js"><link rel="prefetch" href="/assets/js/503.44bad66b.js"><link rel="prefetch" href="/assets/js/504.aca7650b.js"><link rel="prefetch" href="/assets/js/505.5998ff60.js"><link rel="prefetch" href="/assets/js/506.da78a416.js"><link rel="prefetch" href="/assets/js/507.aff2bca1.js"><link rel="prefetch" href="/assets/js/508.a69af73e.js"><link rel="prefetch" href="/assets/js/509.ca6cc10b.js"><link rel="prefetch" href="/assets/js/51.23e52d62.js"><link rel="prefetch" href="/assets/js/510.4113c7e2.js"><link rel="prefetch" href="/assets/js/511.eee75bcf.js"><link rel="prefetch" href="/assets/js/512.163fd3fd.js"><link rel="prefetch" href="/assets/js/513.8844f641.js"><link rel="prefetch" href="/assets/js/514.ac994678.js"><link rel="prefetch" href="/assets/js/515.4bbc68c2.js"><link rel="prefetch" href="/assets/js/516.11f13c34.js"><link rel="prefetch" href="/assets/js/517.69d113a7.js"><link rel="prefetch" href="/assets/js/518.313214d6.js"><link rel="prefetch" href="/assets/js/519.fed86a45.js"><link rel="prefetch" href="/assets/js/52.0052906b.js"><link rel="prefetch" href="/assets/js/520.d28e02c1.js"><link rel="prefetch" href="/assets/js/521.76a6d8e5.js"><link rel="prefetch" href="/assets/js/522.36431cdf.js"><link rel="prefetch" href="/assets/js/523.6aa1dcc6.js"><link rel="prefetch" href="/assets/js/524.cfbcb38c.js"><link rel="prefetch" href="/assets/js/525.e640c924.js"><link rel="prefetch" href="/assets/js/526.2b6f99bf.js"><link rel="prefetch" href="/assets/js/527.3feaedbe.js"><link rel="prefetch" href="/assets/js/528.7fea6593.js"><link rel="prefetch" href="/assets/js/529.b6c8c5fa.js"><link rel="prefetch" href="/assets/js/53.a14286f9.js"><link rel="prefetch" href="/assets/js/530.bd36f6bf.js"><link rel="prefetch" href="/assets/js/531.d841e245.js"><link rel="prefetch" href="/assets/js/532.0a985697.js"><link rel="prefetch" href="/assets/js/533.ad9a4f00.js"><link rel="prefetch" href="/assets/js/534.2a7d4aac.js"><link rel="prefetch" href="/assets/js/535.82c135a5.js"><link rel="prefetch" href="/assets/js/536.65dee757.js"><link rel="prefetch" href="/assets/js/537.6201e43a.js"><link rel="prefetch" href="/assets/js/538.f049f74d.js"><link rel="prefetch" href="/assets/js/539.27e0ab80.js"><link rel="prefetch" href="/assets/js/54.b04c5a95.js"><link rel="prefetch" href="/assets/js/540.e6c83aa3.js"><link rel="prefetch" href="/assets/js/541.115c98fe.js"><link rel="prefetch" href="/assets/js/542.4ecbb86c.js"><link rel="prefetch" href="/assets/js/543.0ce63e05.js"><link rel="prefetch" href="/assets/js/544.d3c4e470.js"><link rel="prefetch" href="/assets/js/545.060f3602.js"><link rel="prefetch" href="/assets/js/546.e52c4d97.js"><link rel="prefetch" href="/assets/js/547.04e6c8eb.js"><link rel="prefetch" href="/assets/js/548.dfa3593d.js"><link rel="prefetch" href="/assets/js/549.53bcead2.js"><link rel="prefetch" href="/assets/js/55.fbb90a23.js"><link rel="prefetch" href="/assets/js/550.881b52ea.js"><link rel="prefetch" href="/assets/js/551.50e24ed5.js"><link rel="prefetch" href="/assets/js/552.bb6ed30c.js"><link rel="prefetch" href="/assets/js/553.ffbc1fb3.js"><link rel="prefetch" href="/assets/js/554.e090942a.js"><link rel="prefetch" href="/assets/js/555.081139b2.js"><link rel="prefetch" href="/assets/js/556.69fd4ccb.js"><link rel="prefetch" href="/assets/js/557.c5db91b9.js"><link rel="prefetch" href="/assets/js/558.d5c6420a.js"><link rel="prefetch" href="/assets/js/559.3315dffc.js"><link rel="prefetch" href="/assets/js/56.15e4531f.js"><link rel="prefetch" href="/assets/js/560.dc07477d.js"><link rel="prefetch" href="/assets/js/561.ae4e0288.js"><link rel="prefetch" href="/assets/js/562.2b0c07d4.js"><link rel="prefetch" href="/assets/js/563.1fda2ae1.js"><link rel="prefetch" href="/assets/js/564.53508bf8.js"><link rel="prefetch" href="/assets/js/565.9bca0fe6.js"><link rel="prefetch" href="/assets/js/566.10462416.js"><link rel="prefetch" href="/assets/js/567.a5c7f8d3.js"><link rel="prefetch" href="/assets/js/568.1a335731.js"><link rel="prefetch" href="/assets/js/569.8f7662f9.js"><link rel="prefetch" href="/assets/js/57.d048b852.js"><link rel="prefetch" href="/assets/js/570.418383b3.js"><link rel="prefetch" href="/assets/js/571.f2dd830b.js"><link rel="prefetch" href="/assets/js/572.a033faf5.js"><link rel="prefetch" href="/assets/js/573.e856599f.js"><link rel="prefetch" href="/assets/js/574.f3d4e9ee.js"><link rel="prefetch" href="/assets/js/575.f1971daa.js"><link rel="prefetch" href="/assets/js/576.9a9293a5.js"><link rel="prefetch" href="/assets/js/577.9dcfab0d.js"><link rel="prefetch" href="/assets/js/578.13cd53c2.js"><link rel="prefetch" href="/assets/js/579.d4415829.js"><link rel="prefetch" href="/assets/js/58.d7adf723.js"><link rel="prefetch" href="/assets/js/580.94de3756.js"><link rel="prefetch" href="/assets/js/581.8d1f75c7.js"><link rel="prefetch" href="/assets/js/582.9637c2ef.js"><link rel="prefetch" href="/assets/js/583.b152c946.js"><link rel="prefetch" href="/assets/js/584.fea17101.js"><link rel="prefetch" href="/assets/js/585.109fe3b0.js"><link rel="prefetch" href="/assets/js/586.9d0ccc89.js"><link rel="prefetch" href="/assets/js/587.625d9e59.js"><link rel="prefetch" href="/assets/js/588.5a67e5d1.js"><link rel="prefetch" href="/assets/js/589.40ad7408.js"><link rel="prefetch" href="/assets/js/59.1c22bee5.js"><link rel="prefetch" href="/assets/js/590.c6b47e20.js"><link rel="prefetch" href="/assets/js/591.b9ecb668.js"><link rel="prefetch" href="/assets/js/592.5cb33641.js"><link rel="prefetch" href="/assets/js/593.c823194c.js"><link rel="prefetch" href="/assets/js/594.1a60d85c.js"><link rel="prefetch" href="/assets/js/595.7171c96b.js"><link rel="prefetch" href="/assets/js/596.df994dae.js"><link rel="prefetch" href="/assets/js/597.26f0d8e2.js"><link rel="prefetch" href="/assets/js/598.4da57856.js"><link rel="prefetch" href="/assets/js/599.9c5d317b.js"><link rel="prefetch" href="/assets/js/6.5a8223c6.js"><link rel="prefetch" href="/assets/js/60.f413108a.js"><link rel="prefetch" href="/assets/js/600.dcb9cd45.js"><link rel="prefetch" href="/assets/js/601.c849924e.js"><link rel="prefetch" href="/assets/js/602.1b1da8be.js"><link rel="prefetch" href="/assets/js/603.4b0218e1.js"><link rel="prefetch" href="/assets/js/604.a190549b.js"><link rel="prefetch" href="/assets/js/605.6d47d3ed.js"><link rel="prefetch" href="/assets/js/606.1bff0ada.js"><link rel="prefetch" href="/assets/js/607.b936c4c3.js"><link rel="prefetch" href="/assets/js/608.3f780076.js"><link rel="prefetch" href="/assets/js/609.8a11d2c0.js"><link rel="prefetch" href="/assets/js/61.3a544786.js"><link rel="prefetch" href="/assets/js/610.979151c6.js"><link rel="prefetch" href="/assets/js/611.1167509a.js"><link rel="prefetch" href="/assets/js/612.5a816980.js"><link rel="prefetch" href="/assets/js/613.0d7a274f.js"><link rel="prefetch" href="/assets/js/614.e1b9c726.js"><link rel="prefetch" href="/assets/js/615.555378d9.js"><link rel="prefetch" href="/assets/js/616.44130343.js"><link rel="prefetch" href="/assets/js/617.2276c4ff.js"><link rel="prefetch" href="/assets/js/618.3f1361dd.js"><link rel="prefetch" href="/assets/js/619.5cf26f9f.js"><link rel="prefetch" href="/assets/js/62.309d2360.js"><link rel="prefetch" href="/assets/js/620.199d4edc.js"><link rel="prefetch" href="/assets/js/621.3ed6463e.js"><link rel="prefetch" href="/assets/js/622.799e92cd.js"><link rel="prefetch" href="/assets/js/623.bbb4ab19.js"><link rel="prefetch" href="/assets/js/624.004c26d6.js"><link rel="prefetch" href="/assets/js/625.6b2f7268.js"><link rel="prefetch" href="/assets/js/626.6191013d.js"><link rel="prefetch" href="/assets/js/627.06434f99.js"><link rel="prefetch" href="/assets/js/628.cc6fdea3.js"><link rel="prefetch" href="/assets/js/629.d0fc9183.js"><link rel="prefetch" href="/assets/js/63.d804fdd6.js"><link rel="prefetch" href="/assets/js/630.583c6f2a.js"><link rel="prefetch" href="/assets/js/631.03f3db76.js"><link rel="prefetch" href="/assets/js/632.25c4219f.js"><link rel="prefetch" href="/assets/js/633.d7181967.js"><link rel="prefetch" href="/assets/js/634.4a7721b5.js"><link rel="prefetch" href="/assets/js/635.3057caf3.js"><link rel="prefetch" href="/assets/js/636.8e0fce94.js"><link rel="prefetch" href="/assets/js/637.31e7d449.js"><link rel="prefetch" href="/assets/js/638.c41f7ae9.js"><link rel="prefetch" href="/assets/js/639.ed69717e.js"><link rel="prefetch" href="/assets/js/64.4416df5a.js"><link rel="prefetch" href="/assets/js/640.69dbb60a.js"><link rel="prefetch" href="/assets/js/641.3a91368e.js"><link rel="prefetch" href="/assets/js/642.77db4756.js"><link rel="prefetch" href="/assets/js/643.9ee92418.js"><link rel="prefetch" href="/assets/js/644.a488caf9.js"><link rel="prefetch" href="/assets/js/645.fef9222a.js"><link rel="prefetch" href="/assets/js/646.9dbabce6.js"><link rel="prefetch" href="/assets/js/647.9927bb01.js"><link rel="prefetch" href="/assets/js/65.6c6975e2.js"><link rel="prefetch" href="/assets/js/66.c8acd9ff.js"><link rel="prefetch" href="/assets/js/67.9d78de9b.js"><link rel="prefetch" href="/assets/js/68.a7042b25.js"><link rel="prefetch" href="/assets/js/69.62e18024.js"><link rel="prefetch" href="/assets/js/7.5469cd27.js"><link rel="prefetch" href="/assets/js/70.c8da543f.js"><link rel="prefetch" href="/assets/js/71.f0391a5f.js"><link rel="prefetch" href="/assets/js/72.2ad7196f.js"><link rel="prefetch" href="/assets/js/73.b473d152.js"><link rel="prefetch" href="/assets/js/74.c5f8716b.js"><link rel="prefetch" href="/assets/js/75.dfc53458.js"><link rel="prefetch" href="/assets/js/76.fbfd608c.js"><link rel="prefetch" href="/assets/js/77.dc2e0214.js"><link rel="prefetch" href="/assets/js/78.cdbdfe94.js"><link rel="prefetch" href="/assets/js/79.d49cc910.js"><link rel="prefetch" href="/assets/js/8.d214e90e.js"><link rel="prefetch" href="/assets/js/80.b48c5ff4.js"><link rel="prefetch" href="/assets/js/81.883f25d0.js"><link rel="prefetch" href="/assets/js/82.08944bcb.js"><link rel="prefetch" href="/assets/js/83.8b938ae3.js"><link rel="prefetch" href="/assets/js/84.f36bf7f5.js"><link rel="prefetch" href="/assets/js/85.df8f94d6.js"><link rel="prefetch" href="/assets/js/86.9e80486e.js"><link rel="prefetch" href="/assets/js/87.beec1c6b.js"><link rel="prefetch" href="/assets/js/88.a018ebba.js"><link rel="prefetch" href="/assets/js/89.0eddefd4.js"><link rel="prefetch" href="/assets/js/9.c5cfaf0b.js"><link rel="prefetch" href="/assets/js/90.58858723.js"><link rel="prefetch" href="/assets/js/91.b0299771.js"><link rel="prefetch" href="/assets/js/92.2fd943da.js"><link rel="prefetch" href="/assets/js/93.8e4f57c0.js"><link rel="prefetch" href="/assets/js/94.f4b65583.js"><link rel="prefetch" href="/assets/js/95.efee0d90.js"><link rel="prefetch" href="/assets/js/96.dc6bfd15.js"><link rel="prefetch" href="/assets/js/97.76854d3b.js"><link rel="prefetch" href="/assets/js/98.a035830a.js"><link rel="prefetch" href="/assets/js/99.173f440e.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.1288603f.js">
<link rel="stylesheet" href="/assets/css/0.styles.70ddaee8.css">
</head>
<body>
<div id="app" data-server-rendered="true"><div class="theme-container"><header class="navbar"><div class="sidebar-button"><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" role="img" viewBox="0 0 448 512" class="icon"><path fill="currentColor" d="M436 124H12c-6.627 0-12-5.373-12-12V80c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12z"></path></svg></div> <a href="/zh/" class="home-link router-link-active"><img src="/img/logo.png" alt=" " class="logo"></a> <div class="links"><div class="search-box"><input aria-label="Search" autocomplete="off" spellcheck="false" value=""> <!----></div> <nav class="nav-links can-hide"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">文档</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external">
Wiki
<!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external">
基金会
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external">
许可证
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external">
安全
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external">
赞助
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external">
致谢
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external">
活动
<!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/UserGuide/V0.11.x/Operation Manual/DML Data Manipulation Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/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/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external">
Wiki
<!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external">
基金会
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external">
许可证
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external">
安全
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external">
赞助
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external">
致谢
<!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external">
活动
<!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/UserGuide/V0.11.x/Operation Manual/DML Data Manipulation Language.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/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 (V0.11.x)</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/V0.11.x/Operation Manual/DDL Data Definition Language.html" class="sidebar-link">DDL (数据定义语言)</a></li><li><a href="/zh/UserGuide/V0.11.x/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/V0.11.x/Operation Manual/Administration.html" class="sidebar-link">权限管理语句</a></li><li><a href="/zh/UserGuide/V0.11.x/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/V0.11.x/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/V0.11.x/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/V0.11.x/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><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。
<center><img src="https://user-images.githubusercontent.com/13203019/51605021-c2ee1500-1f48-11e9-8f6b-ba9b48875a41.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center></p> <h3 id="insert语句的错误处理"><a href="#insert语句的错误处理" class="header-anchor">#</a> INSERT语句的错误处理</h3> <p>若用户向一个不存在的时间序列中插入数据,例如执行以下命令:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB &gt; insert into root.ln.wf02.wt02(timestamp, temperature) values(1,&quot;v1&quot;)
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>由于<code>root.ln.wf02.wt02. temperature</code>时间序列不存在,系统将会返回以下ERROR告知该Timeseries路径不存在:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>Msg: The resultDataType or encoding or compression of the last node temperature is conflicting in the storage group root.ln
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>若用户插入的数据类型与该Timeseries对应的数据类型不一致,例如执行以下命令:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>IoTDB &gt; insert into root.ln.wf02.wt02(timestamp,hardware) values(1,100)
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>系统将会返回以下ERROR告知数据类型有误:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>error: The TEXT data type should be covered by &quot; or '
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</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/V0.11.x/Operation Manual/SQL Reference.html">IoTDB SELECT语句</a>。同时,您也可以使用<a href="/zh/UserGuide/V0.11.x/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/V0.11.x/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> <center><img src="https://user-images.githubusercontent.com/23614968/61280074-da1c0a00-a7e9-11e9-8eb8-3809428043a8.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/23614968/61280328-40a12800-a7ea-11e9-85b9-3b8db67673a3.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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:
<center><img src="https://user-images.githubusercontent.com/23614968/61280449-780fd480-a7ea-11e9-8ed0-70fa9dfda80f.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center></p> <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:
<center><img src="https://user-images.githubusercontent.com/13203019/51577450-dcfe0800-1ef4-11e9-9399-4ba2b2b7fb73.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center></p> <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>更多语法请参照 <a href="/zh/UserGuide/V0.11.x/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 s1,s2 from root.sg1.* GROUP BY DEVICE
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>更多语法请参照 SQL REFERENCE.</p> <p>'disable align' 意味着每条时序就有3列存在。更多语法请参照 SQL REFERENCE.</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><table><thead><tr><th>count(root.ln.wf01.wt01.status)</th></tr></thead> <tbody><tr><td>4</td></tr></tbody></table> <h5 id="按层级统计"><a href="#按层级统计" class="header-anchor">#</a> 按层级统计</h5> <p>通过定义LEVEL来统计指定层级下的数据点个数。</p> <p>这可以用来查询不同层级下的数据点总个数</p> <p>语法是:</p> <p>这个可以用来查询某个路径下的总数据点数</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by level=1;
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><table><thead><tr><th>Time</th> <th>count(root.ln)</th></tr></thead> <tbody><tr><td>0</td> <td>7</td></tr></tbody></table> <div class="language- line-numbers-mode"><pre class="language-text"><code>select count(status) from root.ln.wf01.wt01 group by level=2;
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><table><thead><tr><th>Time</th> <th>count(root.ln.wf01)</th> <th>count(root.ln.wf02)</th></tr></thead> <tbody><tr><td>0</td> <td>4</td> <td>3</td></tr></tbody></table> <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/V0.11.x/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> <center><img src="https://user-images.githubusercontent.com/16079446/69116068-eed51b00-0ac5-11ea-9731-b5a45c5cd224.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/16079446/69116083-f85e8300-0ac5-11ea-84f1-59d934eee96e.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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 where time &gt; 2017-11-01T01:00:00 and temperature &gt; 20 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)这个时间范围的并且满足root.ln.wf01.wt01.temperature &gt; 20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> <center><img src="https://user-images.githubusercontent.com/16079446/69116088-001e2780-0ac6-11ea-9a01-dc45271d1dad.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <p>GROUP BY的SELECT子句里的查询路径必须是聚合函数,否则系统将会抛出如下对应的错误。</p> <center><img src="https://user-images.githubusercontent.com/16079446/69116099-0b715300-0ac6-11ea-8074-84e04797b8c7.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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((5, 40], 5ms);
</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> <table><thead><tr><th>Time</th> <th>count(root.ln.wf01.wt01.status)</th></tr></thead> <tbody><tr><td>10</td> <td>1</td></tr> <tr><td>15</td> <td>2</td></tr> <tr><td>20</td> <td>3</td></tr> <tr><td>25</td> <td>4</td></tr> <tr><td>30</td> <td>4</td></tr> <tr><td>35</td> <td>3</td></tr> <tr><td>40</td> <td>5</td></tr></tbody></table> <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 ([0,20),3ms), level=1;
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><table><thead><tr><th>Time</th> <th>count(root.ln)</th></tr></thead> <tbody><tr><td>0</td> <td>1</td></tr> <tr><td>3</td> <td>0</td></tr> <tr><td>6</td> <td>0</td></tr> <tr><td>9</td> <td>1</td></tr> <tr><td>12</td> <td>3</td></tr> <tr><td>15</td> <td>0</td></tr> <tr><td>18</td> <td>0</td></tr></tbody></table> <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><table><thead><tr><th>Time</th> <th>count(root.ln)</th></tr></thead> <tbody><tr><td>0</td> <td>1</td></tr> <tr><td>3</td> <td>0</td></tr> <tr><td>6</td> <td>0</td></tr> <tr><td>9</td> <td>0</td></tr> <tr><td>12</td> <td>2</td></tr> <tr><td>15</td> <td>0</td></tr> <tr><td>18</td> <td>0</td></tr></tbody></table> <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>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([8, 39), 5m) FILL (int32[PREVIOUSUNTILLAST])
SELECT last_value(temperature) FROM root.ln.wf01.wt01 GROUP BY([8, 39), 5m) FILL (int32[PREVIOUSUNTILLAST, 3m])
</code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>解释:</p> <p>使用 PREVIOUSUNTILLAST 方式填充降频聚合的结果。</p> <p>所有路径必须都伴随聚合函数,否则会报以下错误信息:</p> <center><img src="https://user-images.githubusercontent.com/16079446/69116099-0b715300-0ac6-11ea-8074-84e04797b8c7.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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.speed 的最新数据点</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>&gt; select last speed from root.ln.wf01.wt01
| Time | Path | Value |
| --- | ----------------------- | ----- |
| 5 | root.ln.wf01.wt01.speed | 100 |
</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></div></div><p>示例 2:查询 root.ln.wf01.wt01 下 speed,status,temperature 时间戳大于等于5的最新数据点。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>&gt; select last speed, status, temperature from root.ln.wf01 where time &gt;= 5
| Time | Path | Value |
| --- | ---------------------------- | ----- |
| 5 | root.ln.wf01.wt01.speed | 100 |
| 7 | root.ln.wf01.wt01.status | true |
| 9 | root.ln.wf01.wt01.temperature| 35.7 |
</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><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><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> <center><img src="https://user-images.githubusercontent.com/13203019/51577616-67df0280-1ef5-11e9-9dff-2eb8342074eb.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577679-9f4daf00-1ef5-11e9-8d8b-06a58de6efc1.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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><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> <center><img src="https://user-images.githubusercontent.com/13203019/51577727-d4f29800-1ef5-11e9-8ff3-3bb519da3993.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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>值得注意的是,IoTDB将针对数据类型不支持的填充方法给出错误提示,如下所示:</p> <center><img src="https://user-images.githubusercontent.com/13203019/51577741-e340b400-1ef5-11e9-9238-a4eaf498ab84.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></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/V0.11.x/Operation Manual/SQL Reference.html">LIMIT/SLIMIT</a> 子句和 <a href="/zh/UserGuide/V0.11.x/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/V0.11.x/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> <center><img src="https://user-images.githubusercontent.com/13203019/51577752-efc50c80-1ef5-11e9-9071-da2bbd8b9bdd.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577773-08352700-1ef6-11e9-883f-8d353bef2bdc.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577789-15521600-1ef6-11e9-86ca-d7b2c947367f.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577796-1e42e780-1ef6-11e9-8987-be443000a77e.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/19167280/61517266-6e2fe080-aa39-11e9-8015-154a8e8ace30.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577813-30bd2100-1ef6-11e9-94ef-dbeb450cf319.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577827-39adf280-1ef6-11e9-81b5-876769607cd2.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577840-44688780-1ef6-11e9-8abc-04ae78efa85b.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577855-4d595900-1ef6-11e9-8541-a4accd714b75.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <p>值得注意的是,预期SLIMIT子句将与星形路径或前缀路径一起使用,并且当SLIMIT子句与完整路径查询一起使用时,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 slimit 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> <center><img src="https://user-images.githubusercontent.com/13203019/51577867-577b5780-1ef6-11e9-978c-e02c1294bcc5.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51577879-64984680-1ef6-11e9-9d7b-57dd60fab60e.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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>有关更多语法描述,请阅读SQL REFERENCE。</p> <p>“禁用对齐”指示结果集中每个时间序列都有3列。 有关更多语法描述,请阅读SQL REFERENCE。</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> <center><img src="https://user-images.githubusercontent.com/13203019/51578187-ad9cca80-1ef7-11e9-897a-83e66a0f3d94.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/19167280/61517469-e696a180-aa39-11e9-8ca5-42ea991d520e.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/19167280/61518094-68d39580-aa3b-11e9-993c-fc73c27540f7.png" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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> <center><img src="https://user-images.githubusercontent.com/13203019/51578227-c60ce500-1ef7-11e9-98eb-175beb8d4086.jpg" style="width:100%;max-width:800px;max-height:600px;margin-left:auto;margin-right:auto;display:block;"></center> <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/V0.11.x/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/V0.11.x/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></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/V0.11.x/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/V0.11.x/Operation Manual/Administration.html">
权限管理语句
</a>
</span></p></div> <p style="text-align: center;">Copyright © 2021 The Apache Software Foundation.<br>
Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p> <p style="text-align: center; margin-top: 10px; color: #444">
Contact us: Join QQ Group 659990460 | Add friend <i>tietouqiao</i> and be invited to Wechat Group<br>
see <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> for more</p></main></div><div class="global-ui"></div></div>
<script src="/assets/js/app.008afd2b.js" defer></script><script src="/assets/js/3.9588d9cb.js" defer></script><script src="/assets/js/4.e8b2d372.js" defer></script><script src="/assets/js/500.c468af94.js" defer></script>
</body>
</html>