| <!doctype html> |
| <html lang="zh-CN" data-theme="light"> |
| <head> |
| <meta charset="utf-8" /> |
| <meta name="viewport" content="width=device-width,initial-scale=1" /> |
| <meta name="generator" content="VuePress 2.0.0-rc.26" /> |
| <meta name="theme" content="VuePress Theme Hope 2.0.0-rc.99" /> |
| <style> |
| :root { |
| --vp-c-bg: #fff; |
| } |
| |
| [data-theme="dark"] { |
| --vp-c-bg: #1b1b1f; |
| } |
| |
| html, |
| body { |
| background: var(--vp-c-bg); |
| } |
| </style> |
| <script> |
| const userMode = localStorage.getItem("vuepress-theme-hope-scheme"); |
| const systemDarkMode = |
| window.matchMedia && |
| window.matchMedia("(prefers-color-scheme: dark)").matches; |
| |
| if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) { |
| document.documentElement.setAttribute("data-theme", "dark"); |
| } |
| </script> |
| <script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"标识符","image":[""],"dateModified":"2025-03-04T02:13:10.000Z","author":[]}</script><meta property="og:url" content="https://iotdb.apache.org/zh/UserGuide/latest/SQL-Manual/Syntax-Rule.html"><meta property="og:site_name" content="IoTDB Website"><meta property="og:title" content="标识符"><meta property="og:description" content="标识符 1. 字面值常量 该部分对 IoTDB 中支持的字面值常量进行说明，包括字符串常量、数值型常量、时间戳常量、布尔型常量和空值。 1.1 字符串常量 在 IoTDB 中，字符串是由单引号（'）或双引号（"）字符括起来的字符序列。示例如下： 使用场景 INSERT 或者 SELECT 中用于表达 TEXT 类型数据的场景。 LOAD / REMOV..."><meta property="og:type" content="article"><meta property="og:locale" content="zh-CN"><meta property="og:locale:alternate" content="en-US"><meta property="og:updated_time" content="2025-03-04T02:13:10.000Z"><meta property="article:modified_time" content="2025-03-04T02:13:10.000Z"><link rel="alternate" hreflang="en-us" href="https://iotdb.apache.org/UserGuide/latest/SQL-Manual/Syntax-Rule.html"><script async src="https://widget.kapa.ai/kapa-widget.bundle.js" data-website-id="2d37bfdd-8d98-40ba-9223-9d4f81bfb327" data-project-name="Apache IoTDB" data-project-color="#FFFFFF" data-button-z-index="1999" data-button-padding="4px" data-button-border-radius="4px" data-button-image-height="24px" data-button-image-width="20px" data-button-text-color="#9E2878" data-project-logo="https://iotdb.apache.org/img/logo.svg" data-button-position-right="16px" data-button-position-bottom="8px" data-button-height="56px" data-button-width="48px" data-button-text="Ask" data-modal-override-open-selector="#custom-ask-ai-button" data-modal-image-width="150px" data-modal-title="AI Docs" data-modal-title-color="#9E2878" data-deep-thinking-button-active-bg-color="#F6F7F8" data-deep-thinking-button-active-text-color="#9E2878" data-deep-thinking-button-active-hover-text-color="#9E2878" data-modal-disclaimer="这是一个针对 Apache IoTDB 的定制化大型语言模型，能够访问所有[文档](iotdb.apache.org/docs/)、[GitHub 公开问题、PR 和自述文件](github.com/apache/iotdb)。 |
| |
| 如果您遇到 <Error in verifying browser for feedback submission. Captcha token could not be obtained.> 请确保您能够顺畅访问 Google 服务。" data-user-analytics-fingerprint-enabled="true" data-consent-required="true" data-consent-screen-disclaimer="点击<I agree, let's chat>即表示您同意按照 kapa.ai 的[隐私政策](https://www.kapa.ai/content/privacy-policy)使用 AI 助手。本服务使用 reCAPTCHA，您需要同意 Google 的[隐私政策](https://policies.google.com/privacy)和[服务条款](https://policies.google.com/terms)。继续操作即表示您明确同意 kapa.ai 和 Google 的隐私政策。" data-language="zh"></script><link rel="icon" href="/favicon.ico"><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"><script type="text/javascript">var _paq = window._paq = window._paq || []; |
| /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ |
| _paq.push(["setDoNotTrack", true]); |
| _paq.push(["disableCookies"]); |
| _paq.push(['trackPageView']); |
| _paq.push(['enableLinkTracking']); |
| (function() { |
| var u="https://analytics.apache.org/"; |
| _paq.push(['setTrackerUrl', u+'matomo.php']); |
| _paq.push(['setSiteId', '56']); |
| var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; |
| g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); |
| })(); |
| </script><title>标识符 | IoTDB Website</title><meta name="description" content="标识符 1. 字面值常量 该部分对 IoTDB 中支持的字面值常量进行说明，包括字符串常量、数值型常量、时间戳常量、布尔型常量和空值。 1.1 字符串常量 在 IoTDB 中，字符串是由单引号（'）或双引号（"）字符括起来的字符序列。示例如下： 使用场景 INSERT 或者 SELECT 中用于表达 TEXT 类型数据的场景。 LOAD / REMOV..."> |
| <link rel="preload" href="/assets/style-JraSdRX4.css" as="style"><link rel="stylesheet" href="/assets/style-JraSdRX4.css"> |
| <link rel="modulepreload" href="/assets/app-pmkzp6TS.js"><link rel="modulepreload" href="/assets/Syntax-Rule.html-bAVnNT57.js"> |
| |
| </head> |
| <body> |
| <div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="vp-skip-link sr-only">跳至主要內容</a><!--]--><!--[--><div class="theme-container external-link-icon has-toc" vp-container><!--[--><header id="navbar" class="vp-navbar" vp-navbar><div class="vp-navbar-start"><button type="button" class="vp-toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><a class="route-link vp-brand" href="/zh/" aria-label="带我回家"><img class="vp-nav-logo" src="/logo.png" alt><!----><!----></a><!--]--></div><div class="vp-navbar-center"><!--[--><!--]--></div><div class="vp-navbar-end"><!--[--><!--[--><div id="docsearch-container" style="display:none;"></div><div class="docsearch-placeholder"><button type="button" aria-label="搜索文档" aria-keyshortcuts="Control+k" class="DocSearch DocSearch-Button"><span class="DocSearch-Button-Container"><svg width="20" height="20" viewBox="0 0 24 24" aria-hidden="true" class="DocSearch-Search-Icon"><circle cx="11" cy="11" r="8" stroke="currentColor" fill="none" stroke-width="1.4"></circle><path d="m21 21-4.3-4.3" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">搜索文档</span></span><span class="DocSearch-Button-Keys"><kbd class="DocSearch-Button-Key DocSearch-Button-Key--ctrl">Ctrl</kbd><kbd class="DocSearch-Button-Key">K</kbd></span></button></div><!--]--><div><button id="custom-ask-ai-button"> ✨ Ask AI </button></div><nav class="vp-nav-links"><div class="vp-nav-item hide-in-mobile"><div class="vp-dropdown-wrapper"><button type="button" class="vp-dropdown-title" aria-label="文档"><!--[--><!---->文档<!--]--><span class="arrow"></span><ul class="vp-dropdown"><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/UserGuide/latest/QuickStart/QuickStart_apache.html" aria-label="v2.0.x"><!---->v2.0.x<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/UserGuide/V1.3.x/QuickStart/QuickStart_apache.html" aria-label="v1.3.x"><!---->v1.3.x<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/UserGuide/V1.2.x/QuickStart/QuickStart.html" aria-label="v1.2.x"><!---->v1.2.x<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/UserGuide/V0.13.x/QuickStart/QuickStart.html" aria-label="v0.13.x"><!---->v0.13.x<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><a class="auto-link external-link" href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=177051872" aria-label="系统设计" rel="noopener noreferrer" target="_blank"><!---->系统设计<!----></a></div><div class="vp-nav-item hide-in-mobile"><a class="route-link auto-link" href="/zh/Download/" aria-label="下载"><!---->下载<!----></a></div><div class="vp-nav-item hide-in-mobile"><div class="vp-dropdown-wrapper"><button type="button" class="vp-dropdown-title" aria-label="社区"><!--[--><!---->社区<!--]--><span class="arrow"></span><ul class="vp-dropdown"><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/About.html" aria-label="关于社区"><!---->关于社区<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/Development-Guide.html" aria-label="贡献指南"><!---->贡献指南<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/Community-Partners.html" aria-label="社区伙伴"><!---->社区伙伴<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/Feedback.html" aria-label="交流与反馈"><!---->交流与反馈<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/Events-and-Reports.html" aria-label="活动与报告"><!---->活动与报告<!----></a></li><li class="vp-dropdown-item"><a class="route-link auto-link" href="/zh/Community/Committers.html" aria-label="Committers"><!---->Committers<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><div class="vp-dropdown-wrapper"><button type="button" class="vp-dropdown-title" aria-label="ASF"><!--[--><!---->ASF<!--]--><span class="arrow"></span><ul class="vp-dropdown"><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/" aria-label="基金会" rel="noopener noreferrer" target="_blank"><!---->基金会<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/licenses/" aria-label="许可证" rel="noopener noreferrer" target="_blank"><!---->许可证<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/security/" aria-label="安全" rel="noopener noreferrer" target="_blank"><!---->安全<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/foundation/sponsorship.html" aria-label="赞助" rel="noopener noreferrer" target="_blank"><!---->赞助<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/foundation/thanks.html" aria-label="致谢" rel="noopener noreferrer" target="_blank"><!---->致谢<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://www.apache.org/events/current-event" aria-label="活动" rel="noopener noreferrer" target="_blank"><!---->活动<!----></a></li><li class="vp-dropdown-item"><a class="auto-link external-link" href="https://privacy.apache.org/policies/privacy-policy-public.html" aria-label="隐私" rel="noopener noreferrer" target="_blank"><!---->隐私<!----></a></li></ul></button></div></div></nav><div class="vp-nav-item"><div class="vp-dropdown-wrapper"><button type="button" class="vp-dropdown-title" aria-label="选择语言"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon i18n-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="i18n icon" name="i18n" style="width:1rem;height:1rem;vertical-align:middle;"><path d="M379.392 460.8 494.08 575.488l-42.496 102.4L307.2 532.48 138.24 701.44l-71.68-72.704L234.496 460.8l-45.056-45.056c-27.136-27.136-51.2-66.56-66.56-108.544h112.64c7.68 14.336 16.896 27.136 26.112 35.84l45.568 46.08 45.056-45.056C382.976 312.32 409.6 247.808 409.6 204.8H0V102.4h256V0h102.4v102.4h256v102.4H512c0 70.144-37.888 161.28-87.04 210.944L378.88 460.8zM576 870.4 512 1024H409.6l256-614.4H768l256 614.4H921.6l-64-153.6H576zM618.496 768h196.608L716.8 532.48 618.496 768z"></path></svg><!--]--><span class="arrow"></span><ul class="vp-dropdown"><li class="vp-dropdown-item"><a class="route-link auto-link" href="/UserGuide/latest/SQL-Manual/Syntax-Rule.html" aria-label="English"><!---->English<!----></a></li><li class="vp-dropdown-item"><a class="route-link route-link-active auto-link" href="/zh/UserGuide/latest/SQL-Manual/Syntax-Rule.html" aria-label="简体中文"><!---->简体中文<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><button type="button" class="vp-color-mode-switch" id="color-mode-switch"><svg xmlns="http://www.w3.org/2000/svg" class="icon auto-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="auto icon" name="auto" style="display:none;"><path d="M512 992C246.92 992 32 777.08 32 512S246.92 32 512 32s480 214.92 480 480-214.92 480-480 480zm0-840c-198.78 0-360 161.22-360 360 0 198.84 161.22 360 360 360s360-161.16 360-360c0-198.78-161.22-360-360-360zm0 660V212c165.72 0 300 134.34 300 300 0 165.72-134.28 300-300 300z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="dark icon" name="dark" style="display:none;"><path d="M524.8 938.667h-4.267a439.893 439.893 0 0 1-313.173-134.4 446.293 446.293 0 0 1-11.093-597.334A432.213 432.213 0 0 1 366.933 90.027a42.667 42.667 0 0 1 45.227 9.386 42.667 42.667 0 0 1 10.24 42.667 358.4 358.4 0 0 0 82.773 375.893 361.387 361.387 0 0 0 376.747 82.774 42.667 42.667 0 0 1 54.187 55.04 433.493 433.493 0 0 1-99.84 154.88 438.613 438.613 0 0 1-311.467 128z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="light icon" name="light" style="display:block;"><path d="M952 552h-80a40 40 0 0 1 0-80h80a40 40 0 0 1 0 80zM801.88 280.08a41 41 0 0 1-57.96-57.96l57.96-58a41.04 41.04 0 0 1 58 58l-58 57.96zM512 752a240 240 0 1 1 0-480 240 240 0 0 1 0 480zm0-560a40 40 0 0 1-40-40V72a40 40 0 0 1 80 0v80a40 40 0 0 1-40 40zm-289.88 88.08-58-57.96a41.04 41.04 0 0 1 58-58l57.96 58a41 41 0 0 1-57.96 57.96zM192 512a40 40 0 0 1-40 40H72a40 40 0 0 1 0-80h80a40 40 0 0 1 40 40zm30.12 231.92a41 41 0 0 1 57.96 57.96l-57.96 58a41.04 41.04 0 0 1-58-58l58-57.96zM512 832a40 40 0 0 1 40 40v80a40 40 0 0 1-80 0v-80a40 40 0 0 1 40-40zm289.88-88.08 58 57.96a41.04 41.04 0 0 1-58 58l-57.96-58a41 41 0 0 1 57.96-57.96z"></path></svg></button></div><div class="vp-nav-item vp-action"><a class="vp-action-link" href="https://github.com/apache/iotdb" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" name="github" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><!--]--><button type="button" class="vp-toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span><span class="vp-top"></span><span class="vp-middle"></span><span class="vp-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside id="sidebar" class="vp-sidebar" vp-sidebar><!--[--><p class="vp-sidebar-header iotdb-sidebar-header"><span class="vp-sidebar-title">IoTDB用户手册(V2.0.x)</span></p><div class="sidebar-top-wrapper"><ul class="switch-list"><li class="switch-type switch-active">树模型</li><li class="switch-type">表模型</li></ul><div class="help-icon-wrapper"><div class="help-icon"><span>模型说明</span></div></div></div><!--]--><ul class="vp-sidebar-links"><li><section class="vp-sidebar-group"><p class="vp-sidebar-header"><!----><span class="vp-sidebar-title">IoTDB用户手册(V2.0.x)</span><!----></p><ul class="vp-sidebar-links"></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">关于IoTDB</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">预备知识</span><span class="vp-arrow end"></span></button><!----></section></li><li><a class="route-link auto-link vp-sidebar-link" href="/zh/UserGuide/latest/QuickStart/QuickStart_apache.html" aria-label="快速上手"><!---->快速上手<!----></a></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">安装部署</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">基础功能</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">高级功能</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">AI 能力</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">工具体系</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">应用编程接口</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">生态集成</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable active" type="button"><!----><span class="vp-sidebar-title">SQL手册</span><span class="vp-arrow down"></span></button><ul class="vp-sidebar-links"><li><a class="route-link auto-link vp-sidebar-link" href="/zh/UserGuide/latest/SQL-Manual/QuickStart-Only-Sql_apache.html" aria-label="快速 SQL 体验"><!---->快速 SQL 体验<!----></a></li><li><a class="route-link route-link-active auto-link vp-sidebar-link active" href="/zh/UserGuide/latest/SQL-Manual/Syntax-Rule.html" aria-label="标识符"><!---->标识符<!----></a></li><li><a class="route-link auto-link vp-sidebar-link" href="/zh/UserGuide/latest/SQL-Manual/Keywords.html" aria-label="关键字"><!---->关键字<!----></a></li><li><a class="route-link auto-link vp-sidebar-link" href="/zh/UserGuide/latest/SQL-Manual/SQL-Manual_apache.html" aria-label="SQL手册"><!---->SQL手册<!----></a></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">函数与运算符</span><span class="vp-arrow end"></span></button><!----></section></li></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">技术内幕</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">附录</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">FAQ</span><span class="vp-arrow end"></span></button><!----></section></li></ul><!----></aside><!--[--><main id="main-content" class="vp-page"><!--[--><!----><!----><nav class="vp-breadcrumb disable"></nav><div class="vp-page-title"><h1><!---->标识符</h1><div class="page-info"><!----><!----><span class="page-date-info" aria-label="写作日期📅" data-balloon-pos="up"><svg xmlns="http://www.w3.org/2000/svg" class="icon calendar-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="calendar icon" name="calendar"><path d="M716.4 110.137c0-18.753-14.72-33.473-33.472-33.473-18.753 0-33.473 14.72-33.473 33.473v33.473h66.993v-33.473zm-334.87 0c0-18.753-14.72-33.473-33.473-33.473s-33.52 14.72-33.52 33.473v33.473h66.993v-33.473zm468.81 33.52H716.4v100.465c0 18.753-14.72 33.473-33.472 33.473a33.145 33.145 0 01-33.473-33.473V143.657H381.53v100.465c0 18.753-14.72 33.473-33.473 33.473a33.145 33.145 0 01-33.473-33.473V143.657H180.6A134.314 134.314 0 0046.66 277.595v535.756A134.314 134.314 0 00180.6 947.289h669.74a134.36 134.36 0 00133.94-133.938V277.595a134.314 134.314 0 00-133.94-133.938zm33.473 267.877H147.126a33.145 33.145 0 01-33.473-33.473c0-18.752 14.72-33.473 33.473-33.473h736.687c18.752 0 33.472 14.72 33.472 33.473a33.145 33.145 0 01-33.472 33.473z"></path></svg><span data-allow-mismatch="text">2023/7/10</span><meta property="datePublished" content="2023-07-10T03:11:17.000Z"></span><!----><span class="page-reading-time-info" aria-label="阅读时间⌛" data-balloon-pos="up"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon" name="timer"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>大约 6 分钟</span><meta property="timeRequired" content="PT6M"></span><!----><!----></div><hr></div><!----><div class="" vp-content><!----><div id="markdown-content"><h1 id="标识符" tabindex="-1"><a class="header-anchor" href="#标识符"><span>标识符</span></a></h1><h2 id="_1-字面值常量" tabindex="-1"><a class="header-anchor" href="#_1-字面值常量"><span>1. 字面值常量</span></a></h2><p>该部分对 IoTDB 中支持的字面值常量进行说明，包括字符串常量、数值型常量、时间戳常量、布尔型常量和空值。</p><h3 id="_1-1-字符串常量" tabindex="-1"><a class="header-anchor" href="#_1-1-字符串常量"><span>1.1 字符串常量</span></a></h3><p>在 IoTDB 中，字符串是由<strong>单引号（<code>'</code>）或双引号（<code>"</code>）字符括起来的字符序列</strong>。示例如下：</p><div class="language- line-numbers-mode" data-highlighter="shiki" data-ext="" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-"><span class="line"><span>'a string'</span></span> |
| <span class="line"><span>"another string"</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="使用场景" tabindex="-1"><a class="header-anchor" href="#使用场景"><span>使用场景</span></a></h4><ul><li><p><code>INSERT</code> 或者 <code>SELECT</code> 中用于表达 <code>TEXT</code> 类型数据的场景。</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># </span><span style="color:#C678DD;">insert</span><span style="color:#ABB2BF;"> 示例</span></span> |
| <span class="line"><span style="color:#C678DD;">insert into</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wf02</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wt02</span><span style="color:#ABB2BF;">(</span><span style="color:#C678DD;">timestamp</span><span style="color:#ABB2BF;">,hardware) </span><span style="color:#C678DD;">values</span><span style="color:#ABB2BF;">(</span><span style="color:#D19A66;">1</span><span style="color:#ABB2BF;">, </span><span style="color:#98C379;">'v1'</span><span style="color:#ABB2BF;">)</span></span> |
| <span class="line"><span style="color:#C678DD;">insert into</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wf02</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wt02</span><span style="color:#ABB2BF;">(</span><span style="color:#C678DD;">timestamp</span><span style="color:#ABB2BF;">,hardware) </span><span style="color:#C678DD;">values</span><span style="color:#ABB2BF;">(</span><span style="color:#D19A66;">2</span><span style="color:#ABB2BF;">, </span><span style="color:#98C379;">'\\'</span><span style="color:#ABB2BF;">)</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+--------------------------+</span></span> |
| <span class="line"><span style="color:#ABB2BF;">| </span><span style="color:#C678DD;">Time</span><span style="color:#ABB2BF;">|</span><span style="color:#D19A66;">root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wf02</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wt02</span><span style="color:#ABB2BF;">.hardware|</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+--------------------------+</span></span> |
| <span class="line"><span style="color:#ABB2BF;">|</span><span style="color:#D19A66;">1970</span><span style="color:#ABB2BF;">-</span><span style="color:#D19A66;">01</span><span style="color:#ABB2BF;">-01T08:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">001</span><span style="color:#ABB2BF;">+</span><span style="color:#D19A66;">08</span><span style="color:#ABB2BF;">:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">| v1|</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+--------------------------+</span></span> |
| <span class="line"><span style="color:#ABB2BF;">|</span><span style="color:#D19A66;">1970</span><span style="color:#ABB2BF;">-</span><span style="color:#D19A66;">01</span><span style="color:#ABB2BF;">-01T08:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">002</span><span style="color:#ABB2BF;">+</span><span style="color:#D19A66;">08</span><span style="color:#ABB2BF;">:</span><span style="color:#D19A66;">00</span><span style="color:#ABB2BF;">| \\|</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+--------------------------+</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># </span><span style="color:#C678DD;">select</span><span style="color:#ABB2BF;"> 示例</span></span> |
| <span class="line"><span style="color:#C678DD;">select</span><span style="color:#ABB2BF;"> code </span><span style="color:#C678DD;">from</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">sg1</span><span style="color:#ABB2BF;">.d1 </span><span style="color:#C678DD;">where</span><span style="color:#ABB2BF;"> code </span><span style="color:#C678DD;">in</span><span style="color:#ABB2BF;"> (</span><span style="color:#98C379;">'string1'</span><span style="color:#ABB2BF;">, </span><span style="color:#98C379;">'string2'</span><span style="color:#ABB2BF;">);</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p><code>LOAD</code> / <code>REMOVE</code> / <code>SETTLE</code> 指令中的文件路径。</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># </span><span style="color:#C678DD;">load</span><span style="color:#ABB2BF;"> 示例</span></span> |
| <span class="line"><span style="color:#C678DD;">LOAD</span><span style="color:#98C379;"> 'examplePath'</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># </span><span style="color:#C678DD;">remove</span><span style="color:#ABB2BF;"> 示例</span></span> |
| <span class="line"><span style="color:#C678DD;">REMOVE</span><span style="color:#98C379;"> 'examplePath'</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># SETTLE 示例</span></span> |
| <span class="line"><span style="color:#ABB2BF;">SETTLE </span><span style="color:#98C379;">'examplePath'</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>用户密码。</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 示例，write_pwd 即为用户密码</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#C678DD;"> USER</span><span style="color:#61AFEF;"> ln_write_user</span><span style="color:#98C379;"> 'write_pwd'</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>触发器和 UDF 中的类全类名，示例如下：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 触发器示例，</span><span style="color:#C678DD;">AS</span><span style="color:#ABB2BF;"> 后使用字符串表示类全类名</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#ABB2BF;"> TRIGGER </span><span style="color:#98C379;">`alert-listener-sg1d1s1`</span></span> |
| <span class="line"><span style="color:#C678DD;">AFTER</span><span style="color:#C678DD;"> INSERT</span></span> |
| <span class="line"><span style="color:#C678DD;">ON</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">sg1</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">d1</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">s1</span></span> |
| <span class="line"><span style="color:#C678DD;">AS</span><span style="color:#98C379;"> 'org.apache.iotdb.db.engine.trigger.example.AlertListener'</span></span> |
| <span class="line"><span style="color:#C678DD;">WITH</span><span style="color:#ABB2BF;"> (</span></span> |
| <span class="line"><span style="color:#98C379;"> 'lo'</span><span style="color:#56B6C2;"> =</span><span style="color:#98C379;"> '0'</span><span style="color:#ABB2BF;">, </span></span> |
| <span class="line"><span style="color:#98C379;"> 'hi'</span><span style="color:#56B6C2;"> =</span><span style="color:#98C379;"> '100.0'</span></span> |
| <span class="line"><span style="color:#ABB2BF;">)</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># UDF 示例，</span><span style="color:#C678DD;">AS</span><span style="color:#ABB2BF;"> 后使用字符串表示类全类名</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#C678DD;"> FUNCTION</span><span style="color:#61AFEF;"> example</span><span style="color:#C678DD;"> AS</span><span style="color:#98C379;"> 'org.apache.iotdb.udf.UDTFExample'</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Select 子句中可以为结果集中的值指定别名，别名可以被定义为字符串或者标识符，示例如下：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#C678DD;">select</span><span style="color:#ABB2BF;"> s1 </span><span style="color:#C678DD;">as</span><span style="color:#98C379;"> 'temperature'</span><span style="color:#ABB2BF;">, s2 </span><span style="color:#C678DD;">as</span><span style="color:#98C379;"> 'speed'</span><span style="color:#C678DD;"> from</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wf01</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wt01</span><span style="color:#ABB2BF;">;</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># 表头如下所示</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+-----------|-----+</span></span> |
| <span class="line"><span style="color:#ABB2BF;">| </span><span style="color:#C678DD;">Time</span><span style="color:#ABB2BF;">|temperature|speed|</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+-----------|-----+</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>用于表示键值对，键值对的键和值可以被定义成常量（包括字符串）或者标识符，具体请参考键值对章节。</p></li></ul><h4 id="如何在字符串内使用引号" tabindex="-1"><a class="header-anchor" href="#如何在字符串内使用引号"><span>如何在字符串内使用引号</span></a></h4><ul><li>在单引号引起的字符串内，双引号无需特殊处理。同理，在双引号引起的字符串内，单引号无需特殊处理。</li><li>在单引号引起的字符串里，可以通过双写单引号来表示一个单引号，即单引号 ' 可以表示为 ''。</li><li>在双引号引起的字符串里，可以通过双写双引号来表示一个双引号，即双引号 " 可以表示为 ""。</li></ul><p>字符串内使用引号的示例如下：</p><div class="language- line-numbers-mode" data-highlighter="shiki" data-ext="" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-"><span class="line"><span>'string' // string</span></span> |
| <span class="line"><span>'"string"' // "string"</span></span> |
| <span class="line"><span>'""string""' // ""string""</span></span> |
| <span class="line"><span>'''string' // 'string</span></span> |
| <span class="line"><span></span></span> |
| <span class="line"><span>"string" // string</span></span> |
| <span class="line"><span>"'string'" // 'string'</span></span> |
| <span class="line"><span>"''string''" // ''string''</span></span> |
| <span class="line"><span>"""string" // "string</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="_1-2-数值型常量" tabindex="-1"><a class="header-anchor" href="#_1-2-数值型常量"><span>1.2 数值型常量</span></a></h3><p>数值型常量包括整型和浮点型。</p><p>整型常量是一个数字序列。可以以 <code>+</code> 或 <code>-</code> 开头表示正负。例如：<code>1</code>, <code>-1</code>。</p><p>带有小数部分或由科学计数法表示的为浮点型常量，例如：<code>.1</code>, <code>3.14</code>, <code>-2.23</code>, <code>+1.70</code>, <code>1.2E3</code>, <code>1.2E-3</code>, <code>-1.2E3</code>, <code>-1.2E-3</code>。</p><p>在 IoTDB 中，<code>INT32</code> 和 <code>INT64</code> 表示整数类型（计算是准确的），<code>FLOAT</code> 和 <code>DOUBLE</code> 表示浮点数类型（计算是近似的）。</p><p>在浮点上下文中可以使用整数，它会被解释为等效的浮点数。</p><h3 id="_1-3-时间戳常量" tabindex="-1"><a class="header-anchor" href="#_1-3-时间戳常量"><span>1.3 时间戳常量</span></a></h3><p>时间戳是一个数据到来的时间点，在 IoTDB 中分为绝对时间戳和相对时间戳。详细信息可参考 <a class="route-link" href="/zh/UserGuide/latest/Background-knowledge/Data-Type.html">数据类型文档</a>。</p><p>特别地，<code>NOW()</code>表示语句开始执行时的服务端系统时间戳。</p><h3 id="_1-4-布尔型常量" tabindex="-1"><a class="header-anchor" href="#_1-4-布尔型常量"><span>1.4 布尔型常量</span></a></h3><p>布尔值常量 <code>TRUE</code> 和 <code>FALSE</code> 分别等价于 <code>1</code> 和 <code>0</code>，它们对大小写不敏感。</p><h3 id="_1-5-空值" tabindex="-1"><a class="header-anchor" href="#_1-5-空值"><span>1.5 空值</span></a></h3><p><code>NULL</code>值表示没有数据。<code>NULL</code>对大小写不敏感。</p><h2 id="_2-标识符" tabindex="-1"><a class="header-anchor" href="#_2-标识符"><span>2. 标识符</span></a></h2><h3 id="_2-1-使用场景" tabindex="-1"><a class="header-anchor" href="#_2-1-使用场景"><span>2.1 使用场景</span></a></h3><p>在 IoTDB 中，触发器名称、UDF函数名、元数据模板名称、用户与角色名、连续查询标识、Pipe、PipeSink、键值对中的键和值、别名等可以作为标识符。</p><h3 id="_2-2-约束" tabindex="-1"><a class="header-anchor" href="#_2-2-约束"><span>2.2 约束</span></a></h3><p>请注意，此处约束是标识符的通用约束，具体标识符可能还附带其它约束条件，如用户名限制字符数大于等于4，更严格的约束请参考具体标识符相关的说明文档。</p><p><strong>标识符命名有以下约束：</strong></p><ul><li>不使用反引号括起的标识符中，允许出现以下字符： <ul><li>[ 0-9 a-z A-Z _ ] （字母，数字，下划线）</li><li>['\u2E80'..'\u9FFF'] （UNICODE 中文字符）</li></ul></li></ul><h3 id="_2-3-反引号" tabindex="-1"><a class="header-anchor" href="#_2-3-反引号"><span>2.3 反引号</span></a></h3><p><strong>如果出现如下情况，标识符需要使用反引号进行引用：</strong></p><ul><li>标识符包含不允许的特殊字符。</li><li>标识符为实数。</li></ul><h4 id="如何在反引号引起的标识符中使用引号" tabindex="-1"><a class="header-anchor" href="#如何在反引号引起的标识符中使用引号"><span>如何在反引号引起的标识符中使用引号</span></a></h4><p><strong>在反引号引起的标识符中可以直接使用单引号和双引号。</strong></p><p><strong>在用反引号引用的标识符中，可以通过双写反引号的方式使用反引号，即 ` 可以表示为 ``。</strong></p><p>示例如下：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建模板 t1</span><span style="color:#98C379;">`t</span></span> |
| <span class="line"><span style="color:#98C379;">create device template `</span><span style="color:#ABB2BF;">t1</span><span style="color:#98C379;">``</span><span style="color:#ABB2BF;">t</span><span style="color:#98C379;">` </span></span> |
| <span class="line"><span style="color:#98C379;">(temperature FLOAT encoding=RLE, status BOOLEAN encoding=PLAIN compression=SNAPPY)</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#98C379;"># 创建模板 t1't"t</span></span> |
| <span class="line"><span style="color:#98C379;">create device template `</span><span style="color:#ABB2BF;">t1</span><span style="color:#98C379;">'t"t` </span></span> |
| <span class="line"><span style="color:#98C379;">(temperature FLOAT encoding=RLE, status BOOLEAN encoding=PLAIN compression=SNAPPY)</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="反引号相关示例" tabindex="-1"><a class="header-anchor" href="#反引号相关示例"><span>反引号相关示例</span></a></h4><ul><li><p>触发器名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建触发器 alert.</span><span style="color:#98C379;">`listener-sg1d1s1</span></span> |
| <span class="line"><span style="color:#98C379;">CREATE TRIGGER `</span><span style="color:#ABB2BF;">alert.</span><span style="color:#98C379;">``</span><span style="color:#ABB2BF;">listener-sg1d1s1</span><span style="color:#98C379;">`</span></span> |
| <span class="line"><span style="color:#98C379;">AFTER INSERT</span></span> |
| <span class="line"><span style="color:#98C379;">ON root.sg1.d1.s1</span></span> |
| <span class="line"><span style="color:#98C379;">AS 'org.apache.iotdb.db.engine.trigger.example.AlertListener'</span></span> |
| <span class="line"><span style="color:#98C379;">WITH (</span></span> |
| <span class="line"><span style="color:#98C379;"> 'lo' = '0', </span></span> |
| <span class="line"><span style="color:#98C379;"> 'hi' = '100.0'</span></span> |
| <span class="line"><span style="color:#98C379;">)</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>UDF 名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建名为 </span><span style="color:#D19A66;">111</span><span style="color:#ABB2BF;"> 的 UDF，</span><span style="color:#D19A66;">111</span><span style="color:#ABB2BF;"> 为实数，所以需要用反引号引用。</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#C678DD;"> FUNCTION</span><span style="color:#ABB2BF;"> `</span><span style="color:#61AFEF;">111</span><span style="color:#ABB2BF;">` </span><span style="color:#C678DD;">AS</span><span style="color:#98C379;"> 'org.apache.iotdb.udf.UDTFExample'</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>元数据模板名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建名为 </span><span style="color:#D19A66;">111</span><span style="color:#ABB2BF;"> 的元数据模板，</span><span style="color:#D19A66;">111</span><span style="color:#ABB2BF;"> 为实数，需要用反引号引用。</span></span> |
| <span class="line"><span style="color:#C678DD;">create</span><span style="color:#ABB2BF;"> device template </span><span style="color:#98C379;">`111`</span><span style="color:#ABB2BF;"> </span></span> |
| <span class="line"><span style="color:#ABB2BF;">(temperature </span><span style="color:#C678DD;">FLOAT</span><span style="color:#C678DD;"> encoding</span><span style="color:#56B6C2;">=</span><span style="color:#ABB2BF;">RLE, </span><span style="color:#C678DD;">status</span><span style="color:#C678DD;"> BOOLEAN</span><span style="color:#C678DD;"> encoding</span><span style="color:#56B6C2;">=</span><span style="color:#ABB2BF;">PLAIN </span><span style="color:#C678DD;">compression</span><span style="color:#56B6C2;">=</span><span style="color:#ABB2BF;">SNAPPY)</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>用户名、角色名出现上述特殊情况时需使用反引号引用，同时无论是否使用反引号引用，用户名、角色名中均不允许出现空格，具体请参考权限管理章节中的说明。</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建用户 special</span><span style="color:#98C379;">`user.</span></span> |
| <span class="line"><span style="color:#98C379;">CREATE USER `</span><span style="color:#ABB2BF;">special</span><span style="color:#98C379;">``</span><span style="color:#ABB2BF;">user.</span><span style="color:#98C379;">` 'write_pwd'</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#98C379;"># 创建角色 111</span></span> |
| <span class="line"><span style="color:#98C379;">CREATE ROLE `</span><span style="color:#D19A66;">111</span><span style="color:#98C379;">`</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>连续查询标识出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建连续查询 </span><span style="color:#D19A66;">test</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">cq</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#ABB2BF;"> CONTINUOUS QUERY </span><span style="color:#98C379;">`test.cq`</span><span style="color:#ABB2BF;"> </span></span> |
| <span class="line"><span style="color:#C678DD;">BEGIN</span><span style="color:#ABB2BF;"> </span></span> |
| <span class="line"><span style="color:#C678DD;"> SELECT</span><span style="color:#ABB2BF;"> max_value(temperature) </span></span> |
| <span class="line"><span style="color:#C678DD;"> INTO</span><span style="color:#ABB2BF;"> temperature_max </span></span> |
| <span class="line"><span style="color:#C678DD;"> FROM</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.*.* </span></span> |
| <span class="line"><span style="color:#C678DD;"> GROUP BY</span><span style="color:#C678DD;"> time</span><span style="color:#ABB2BF;">(10s) </span></span> |
| <span class="line"><span style="color:#C678DD;">END</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Pipe、PipeSink 名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#ABB2BF;"># 创建 PipeSink test.*</span><span style="color:#D19A66;">1</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#ABB2BF;"> PIPESINK </span><span style="color:#98C379;">`test.*1`</span><span style="color:#C678DD;"> AS</span><span style="color:#ABB2BF;"> IoTDB (</span><span style="color:#98C379;">'ip'</span><span style="color:#56B6C2;"> =</span><span style="color:#98C379;"> '输入你的IP'</span><span style="color:#ABB2BF;">)</span></span> |
| <span class="line"></span> |
| <span class="line"><span style="color:#ABB2BF;"># 创建 Pipe test.*</span><span style="color:#D19A66;">2</span></span> |
| <span class="line"><span style="color:#C678DD;">CREATE</span><span style="color:#ABB2BF;"> PIPE </span><span style="color:#98C379;">`test.*2`</span><span style="color:#C678DD;"> TO</span><span style="color:#98C379;"> `test.*1`</span><span style="color:#C678DD;"> FROM</span><span style="color:#ABB2BF;"> </span></span> |
| <span class="line"><span style="color:#ABB2BF;">(</span><span style="color:#C678DD;">select</span><span style="color:#ABB2BF;"> ** </span><span style="color:#C678DD;">from</span><span style="color:#C678DD;"> root</span><span style="color:#C678DD;"> WHERE</span><span style="color:#C678DD;"> time</span><span style="color:#56B6C2;">>=</span><span style="color:#ABB2BF;">yyyy-mm-dd HH:MM:SS) </span><span style="color:#C678DD;">WITH</span><span style="color:#98C379;"> 'SyncDelOp'</span><span style="color:#56B6C2;"> =</span><span style="color:#98C379;"> 'true'</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>Select 子句中可以结果集中的值指定别名，别名可以被定义为字符串或者标识符，示例如下：</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#C678DD;">select</span><span style="color:#ABB2BF;"> s1 </span><span style="color:#C678DD;">as</span><span style="color:#ABB2BF;"> temperature, s2 </span><span style="color:#C678DD;">as</span><span style="color:#ABB2BF;"> speed </span><span style="color:#C678DD;">from</span><span style="color:#D19A66;"> root</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">ln</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wf01</span><span style="color:#ABB2BF;">.</span><span style="color:#D19A66;">wt01</span><span style="color:#ABB2BF;">;</span></span> |
| <span class="line"><span style="color:#ABB2BF;"># 表头如下所示</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+-----------+-----+</span></span> |
| <span class="line"><span style="color:#ABB2BF;">| </span><span style="color:#C678DD;">Time</span><span style="color:#ABB2BF;">|temperature|speed|</span></span> |
| <span class="line"><span style="color:#ABB2BF;">+</span><span style="color:#7F848E;font-style:italic;">-----------------------------+-----------+-----+</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>用于表示键值对，键值对的键和值可以被定义成常量（包括字符串）或者标识符，具体请参考键值对章节。</p></li><li><p>路径中非 database 的节点允许含有<code>*</code>符号，在使用时需要把该节点用反引号括起来（如下），但是此种用法只建议在在路径中不可避免含有<code>*</code>时使用。</p><div class="language-sql line-numbers-mode" data-highlighter="shiki" data-ext="sql" style="background-color:#282c34;color:#abb2bf;"><pre class="shiki one-dark-pro vp-code"><code class="language-sql"><span class="line"><span style="color:#98C379;">`root.db.*`</span></span></code></pre><div class="line-numbers" aria-hidden="true" style="counter-reset:line-number 0;"><div class="line-number"></div></div></div></li></ul></div><!----><!----><!----></div><footer class="vp-page-meta"><div class="vp-meta-item edit-link"><a class="auto-link external-link vp-meta-label" href="https://github.com/apache/iotdb-docs/edit/main/src/zh/UserGuide/latest/SQL-Manual/Syntax-Rule.md" aria-label="发现错误？在 GitHub 上编辑此页" rel="noopener noreferrer" target="_blank"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon" name="edit"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->发现错误？在 GitHub 上编辑此页<!----></a></div><div class="vp-meta-item git-info"><div class="update-time"><span class="vp-meta-label">最近更新: </span><time class="vp-meta-info" datetime="2025-03-04T02:13:10.000Z" data-allow-mismatch>2025/3/4 02:13</time></div><!----></div></footer><nav class="vp-page-nav"><a class="route-link auto-link prev" href="/zh/UserGuide/latest/SQL-Manual/QuickStart-Only-Sql_apache.html" aria-label="快速 SQL 体验"><div class="hint"><span class="arrow start"></span>上一页</div><div class="link"><!---->快速 SQL 体验</div></a><a class="route-link auto-link next" href="/zh/UserGuide/latest/SQL-Manual/Keywords.html" aria-label="关键字"><div class="hint">下一页<span class="arrow end"></span></div><div class="link">关键字<!----></div></a></nav><!----><!----><!--]--></main><!--]--><footer class="site-footer"><span id="doc-version" style="display:none;">latest</span><p class="copyright-text">版权所有 © 2026 Apache软件基金会。 |
| Apache IoTDB，IoTDB，Apache，Apache 羽毛标志和 Apache IoTDB 项目标志是 Apache 软件基金会在所有国家的注册商标或商标</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"><strong>有问题吗？</strong> 在 QQ、微信或 Slack 上联系我们。 <a href="https://github.com/apache/iotdb/issues/1995">立即加入社区</a></p></footer></div><!--]--><!--]--><!--[--><!----><!--]--><!--]--></div> |
| <script type="module" src="/assets/app-pmkzp6TS.js" defer></script> |
| </body> |
| </html> |
