TiDB 特有的函数 | PingCAP 文档中心

相关文章推荐

痴情的葫芦 · 命令行构建Unity项目 - 赵青青 - 博客园· 1 年前 ·

行走的烤土司 · Nat. Commun. | ...· 1 年前 ·

焦虑的脸盆 · js获取当前日期，格式为YYYY-MM-DD ...· 1 年前 ·

路过的毛衣 · 混合现实技术在口腔颌面部肿瘤手术中的应用 ...· 1 年前 ·

失望的烈马 · 在Excel ...· 1 年前 ·

</noscript><div id="___gatsby"><div style="outline:none" tabindex="-1" id="gatsby-focus-wrapper"><style data-emotion="css 6ko3zs">.css-6ko3zs{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;width:100%;box-sizing:border-box;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;position:fixed;z-index:1100;top:0;left:auto;right:0;background-color:#1976d2;color:#fff;background-color:#f9f9f9;border-bottom:1px solid #e5e5e5;box-shadow:0px 1px 6px rgba(0, 0, 0, 0.08);height:5rem;}@media print{.css-6ko3zs{}}</style><style data-emotion="css foju0o">.css-foju0o{background-color:#fff;color:rgba(0, 0, 0, 0.87);-webkit-transition:box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;box-shadow:0px 2px 4px -1px rgba(0,0,0,0.2),0px 4px 5px 0px rgba(0,0,0,0.14),0px 1px 10px 0px rgba(0,0,0,0.12);display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;width:100%;box-sizing:border-box;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;position:fixed;z-index:1100;top:0;left:auto;right:0;background-color:#1976d2;color:#fff;background-color:#f9f9f9;border-bottom:1px solid #e5e5e5;box-shadow:0px 1px 6px rgba(0, 0, 0, 0.08);height:5rem;}@media print{.css-foju0o{}}</style><header class="MuiPaper-root MuiPaper-elevation MuiPaper-elevation4 MuiAppBar-root MuiAppBar-colorPrimary MuiAppBar-positionFixed mui-fixed css-foju0o"><style data-emotion="css 1xw2ef0">.css-1xw2ef0{position:relative;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-left:16px;padding-right:16px;min-height:56px;height:100%;}@media (min-width:600px){.css-1xw2ef0{padding-left:24px;padding-right:24px;}}@media (min-width:0px){@media (orientation: landscape){.css-1xw2ef0{min-height:48px;}}}@media (min-width:600px){.css-1xw2ef0{min-height:64px;}}@media (min-width:900px){.css-1xw2ef0{padding-left:2rem;padding-right:2rem;}}</style><div class="MuiToolbar-root MuiToolbar-gutters MuiToolbar-regular css-1xw2ef0"><style data-emotion="css 16bbyrv">.css-16bbyrv{text-align:center;-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto;font-size:1.5rem;padding:8px;border-radius:50%;overflow:visible;color:rgba(0, 0, 0, 0.54);-webkit-transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-16bbyrv:hover{background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-16bbyrv:hover{background-color:transparent;}}.css-16bbyrv.Mui-disabled{background-color:transparent;color:rgba(0, 0, 0, 0.26);}@media (min-width:1200px){.css-16bbyrv{;}}</style><style data-emotion="css iuftj9">.css-iuftj9{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;position:relative;box-sizing:border-box;-webkit-tap-highlight-color:transparent;background-color:transparent;outline:0;border:0;margin:0;border-radius:0;padding:0;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;vertical-align:middle;-moz-appearance:none;-webkit-appearance:none;-webkit-text-decoration:none;text-decoration:none;color:inherit;text-align:center;-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto;font-size:1.5rem;padding:8px;border-radius:50%;overflow:visible;color:rgba(0, 0, 0, 0.54);-webkit-transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-iuftj9::-moz-focus-inner{border-style:none;}.css-iuftj9.Mui-disabled{pointer-events:none;cursor:default;}@media print{.css-iuftj9{-webkit-print-color-adjust:exact;color-adjust:exact;}}.css-iuftj9:hover{background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-iuftj9:hover{background-color:transparent;}}.css-iuftj9.Mui-disabled{background-color:transparent;color:rgba(0, 0, 0, 0.26);}@media (min-width:1200px){.css-iuftj9{;}}</style><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeMedium css-iuftj9" tabindex="0" type="button" aria-label="menu"><style data-emotion="css vubbuv">.css-vubbuv{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="MenuIcon"><path d="M3 18h18v-2H3v2zm0-5h18v-2H3v2zm0-7v2h18V6H3z"/></svg></button><style data-emotion="css a3xyjy">.css-a3xyjy{z-index:1200;}</style><style data-emotion="css 13tqxrv">@media (min-width:0px){.css-13tqxrv{;}}@media (min-width:900px){.css-13tqxrv{display:block;}}</style><div class="MuiBox-root css-13tqxrv"><style data-emotion="css tx8jsd">.css-tx8jsd{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;}</style><a class="MuiTypography-root MuiTypography-body1 css-tx8jsd" target="_blank" href="https://cn.pingcap.com/" style="text-decoration:none"><style data-emotion="css uz5bjn">.css-uz5bjn{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;width:6.75rem;}@media (min-width:0px){.css-uz5bjn{;}}@media (min-width:600px){.css-uz5bjn{display:block;}}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-uz5bjn" focusable="false" aria-hidden="true" viewbox="0 0 769.89 203.08"><g id="Layer_2" data-name="Layer 2"><g id="Layer_1-2" data-name="Layer 1"><path fill="#082265" d="M100.11,47.34l-88-25.1A9.5,9.5,0,0,0,0,31.38v162.2a9.51,9.51,0,0,0,9.48,9.5,9.35,9.35,0,0,0,2.22-.26l88-21h0a9.48,9.48,0,0,0,7.3-9.25V56.48A9.54,9.54,0,0,0,100.11,47.34Z"/><path fill="#00aeef" d="M160.05,41.57a9.55,9.55,0,0,0-6.88-9.11L41.16.37A9.5,9.5,0,0,0,29,9.51V132.59a9.47,9.47,0,0,0,11.72,9.23l112.14-27a9.47,9.47,0,0,0,7.28-9.26Z"/><path fill="#303eab" d="M100.11,47.34,29,27.07V132.59a9.47,9.47,0,0,0,11.72,9.23L107,125.88V56.48A9.54,9.54,0,0,0,100.11,47.34Z"/><path fill="#082265" d="M576.1,126.26h0l-.23.37a40.12,40.12,0,0,1-13.72,13.09,36.62,36.62,0,0,1-18.78,5.43c-10.94,0-20.51-4.36-28.42-13a43.82,43.82,0,0,1-11.37-31,43.09,43.09,0,0,1,11.74-29.38c7.62-8.17,16.81-12.31,27.3-12.31,14.37-.13,25.2,5.8,33.13,18.13L576,78h.22l9.33-5.77a51.65,51.65,0,0,0-15.42-16.39,48.17,48.17,0,0,0-26.73-8.09A46.85,46.85,0,0,0,507.66,63c-9.94,10.23-15,23.28-15,38.77,0,15,5,28.08,14.84,38.9,9.81,10.64,21.69,16,35.33,16h.51c17.92-.37,32.69-9.06,42.11-24.6Z"/><polygon fill="#082265" points="645.84 49.09 633.16 49.09 586.01 154.63 601.05 154.63 615.63 119.55 615.65 119.55 620.8 108.59 620.78 108.59 639.76 64.05 658.36 108.59 631.66 108.59 626.79 119.55 662.69 119.55 677.4 154.63 690.66 154.63 645.84 49.09"/><path fill="#082265" d="M759.63,58.75c-7-6.32-15.81-9.52-26.18-9.52H699.3v105.4h12.44V113.34h0V102.25h0V60.59H734a24.73,24.73,0,0,1,16.22,5.63,18.12,18.12,0,0,1,7.37,14c.39,6.62-1.77,11.88-6.61,16.07a23.43,23.43,0,0,1-16.31,6H721.77v11.09h14.91a33.34,33.34,0,0,0,23.23-8.85,29,29,0,0,0,10-21.91C770,72.89,766.58,64.87,759.63,58.75Z"/><rect fill="#082265" x="296.25" y="51.17" width="12.44" height="12.44"/><rect fill="#082265" x="296.25" y="79.04" width="12.44" height="75.74"/><path fill="#082265" d="M483.63,147.21V114.69a38.6,38.6,0,0,0-12.25-29.2c-8.22-8.22-18.1-12.27-29.35-12a39.17,39.17,0,0,0-27.82,12.54,40.08,40.08,0,0,0-11.29,28.49,41,41,0,0,0,12.24,29.59c8.19,8.18,18,12.12,29.22,11.71a38.78,38.78,0,0,0,27.48-12.33v5.17m0,0c0,6.88-2.73,12.89-8.11,17.88a27.1,27.1,0,0,1-19,7.73,27.83,27.83,0,0,1-16.93-5.64,25.92,25.92,0,0,1-9-10.54l-9.52,5.5a36.63,36.63,0,0,0,9.94,12c6.6,5.25,14.75,8.13,24.23,8.54.59,0,1.18,0,1.77,0a40.89,40.89,0,0,0,26-9.25c8.17-6.52,12.32-14.86,12.32-24.8v-2.95m-12-31.74a29.23,29.23,0,0,1-8.41,20.22,25.68,25.68,0,0,1-19.5,8.38,27.3,27.3,0,0,1-20.2-8.39,28.22,28.22,0,0,1-8.66-20.34,28.66,28.66,0,0,1,7.88-20.61,27.21,27.21,0,0,1,19.53-9.45c.51,0,1,0,1.5,0,7.61,0,14,2.85,19.45,8.69A28.51,28.51,0,0,1,471.59,115.47Z"/><path fill="#082265" d="M274.1,58.75c-7-6.32-15.81-9.52-26.19-9.52H213.76v105.4h12.45V113.34h0V102.25h0V60.59h22.24a24.73,24.73,0,0,1,16.23,5.63,18.12,18.12,0,0,1,7.37,14c.39,6.62-1.77,11.88-6.61,16.07a23.43,23.43,0,0,1-16.31,6H236.24v11.09h14.91a33.34,33.34,0,0,0,23.23-8.85,29,29,0,0,0,10-21.91C284.5,72.89,281.05,64.87,274.1,58.75Z"/><path fill="#082265" d="M357.54,74.41c-9.92,0-18.3,3.43-24.94,10.2s-9.91,15.24-9.91,25.33v44.53h12V108.86a21.82,21.82,0,0,1,6.75-16.1A22.08,22.08,0,0,1,357.54,86a21.49,21.49,0,0,1,15.82,6.75,21.86,21.86,0,0,1,6.89,16.1v45.61h12V109.94c0-10.09-3.34-18.61-9.92-25.33A33.47,33.47,0,0,0,357.54,74.41Z"/></g></g></svg></a></div><style data-emotion="css 5qlh60">.css-5qlh60{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;padding-left:2rem;height:100%;}.css-5qlh60&gt;:not(style)+:not(style){margin:0;margin-left:24px;}@media (min-width:0px){.css-5qlh60{;}}@media (min-width:900px){.css-5qlh60{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;}}</style><div class="css-5qlh60"><style data-emotion="css kiou0g">.css-kiou0g{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-top:0.25rem;padding-bottom:0.25rem;}</style><div class="MuiBox-root css-kiou0g"><a style="text-decoration:none" hreflang="zh" href="/zh/"><style data-emotion="css 2jgwiy">.css-2jgwiy{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;color:#282a36;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Helvetica,Arial,"IBM Plex Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji";display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;gap:4px;}</style><div class="MuiTypography-root MuiTypography-body1 css-2jgwiy">文档中心</div></a></div><div class="MuiBox-root css-kiou0g"><a style="text-decoration:none" hreflang="zh" href="/zh/tidb/stable"><div class="MuiTypography-root MuiTypography-body1 css-2jgwiy">TiDB</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-tx8jsd" target="_blank" href="https://asktug.com/" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-2jgwiy">社区</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-tx8jsd" target="_blank" href="https://cn.pingcap.com/contact/" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-2jgwiy">联系我们</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-tx8jsd" target="_blank" href="https://cn.pingcap.com/product/#SelectProduct" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-2jgwiy"><style data-emotion="css xnd31y">.css-xnd31y{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:inherit;padding-top:0.5rem;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-xnd31y" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="DownloadIcon"><path d="M5 20h14v-2H5v2zM19 9h-4V3H9v6H5l7 7 7-7z"/></svg></div></a></div></div><style data-emotion="css 1vn3uc0">.css-1vn3uc0{color:#282a36;}@media (min-width:900px){.css-1vn3uc0{;}}</style><div class="MuiBox-root css-1vn3uc0"><style data-emotion="css btg76o">.css-btg76o{text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;border-color:currentColor;box-shadow:none;}.css-btg76o:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-btg76o:hover{background-color:transparent;}}.css-btg76o.Mui-disabled{color:rgba(0, 0, 0, 0.26);}.css-btg76o:hover{box-shadow:none;}.css-btg76o.Mui-focusVisible{box-shadow:none;}.css-btg76o:active{box-shadow:none;}.css-btg76o.Mui-disabled{box-shadow:none;}</style><style data-emotion="css 1ei260h">.css-1ei260h{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;position:relative;box-sizing:border-box;-webkit-tap-highlight-color:transparent;background-color:transparent;outline:0;border:0;margin:0;border-radius:0;padding:0;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;vertical-align:middle;-moz-appearance:none;-webkit-appearance:none;-webkit-text-decoration:none;text-decoration:none;color:inherit;text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;border-color:currentColor;box-shadow:none;}.css-1ei260h::-moz-focus-inner{border-style:none;}.css-1ei260h.Mui-disabled{pointer-events:none;cursor:default;}@media print{.css-1ei260h{-webkit-print-color-adjust:exact;color-adjust:exact;}}.css-1ei260h:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-1ei260h:hover{background-color:transparent;}}.css-1ei260h.Mui-disabled{color:rgba(0, 0, 0, 0.26);}.css-1ei260h:hover{box-shadow:none;}.css-1ei260h.Mui-focusVisible{box-shadow:none;}.css-1ei260h:active{box-shadow:none;}.css-1ei260h.Mui-disabled{box-shadow:none;}</style><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textInherit MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-colorInherit MuiButton-disableElevation css-1ei260h" tabindex="0" type="button" id="header-nav-items" aria-haspopup="true"><style data-emotion="css 6xugel">.css-6xugel{display:inherit;margin-right:8px;margin-left:-4px;}.css-6xugel&gt;*:nth-of-type(1){font-size:20px;}</style><span class="MuiButton-startIcon MuiButton-iconSizeMedium css-6xugel"><style data-emotion="css 1x9zct">.css-1x9zct{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;width:6.75rem;height:1.5rem;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1x9zct" focusable="false" aria-hidden="true" viewbox="0 0 769.89 203.08"><g id="Layer_2" data-name="Layer 2"><g id="Layer_1-2" data-name="Layer 1"><path fill="#082265" d="M100.11,47.34l-88-25.1A9.5,9.5,0,0,0,0,31.38v162.2a9.51,9.51,0,0,0,9.48,9.5,9.35,9.35,0,0,0,2.22-.26l88-21h0a9.48,9.48,0,0,0,7.3-9.25V56.48A9.54,9.54,0,0,0,100.11,47.34Z"/><path fill="#00aeef" d="M160.05,41.57a9.55,9.55,0,0,0-6.88-9.11L41.16.37A9.5,9.5,0,0,0,29,9.51V132.59a9.47,9.47,0,0,0,11.72,9.23l112.14-27a9.47,9.47,0,0,0,7.28-9.26Z"/><path fill="#303eab" d="M100.11,47.34,29,27.07V132.59a9.47,9.47,0,0,0,11.72,9.23L107,125.88V56.48A9.54,9.54,0,0,0,100.11,47.34Z"/><path fill="#082265" d="M576.1,126.26h0l-.23.37a40.12,40.12,0,0,1-13.72,13.09,36.62,36.62,0,0,1-18.78,5.43c-10.94,0-20.51-4.36-28.42-13a43.82,43.82,0,0,1-11.37-31,43.09,43.09,0,0,1,11.74-29.38c7.62-8.17,16.81-12.31,27.3-12.31,14.37-.13,25.2,5.8,33.13,18.13L576,78h.22l9.33-5.77a51.65,51.65,0,0,0-15.42-16.39,48.17,48.17,0,0,0-26.73-8.09A46.85,46.85,0,0,0,507.66,63c-9.94,10.23-15,23.28-15,38.77,0,15,5,28.08,14.84,38.9,9.81,10.64,21.69,16,35.33,16h.51c17.92-.37,32.69-9.06,42.11-24.6Z"/><polygon fill="#082265" points="645.84 49.09 633.16 49.09 586.01 154.63 601.05 154.63 615.63 119.55 615.65 119.55 620.8 108.59 620.78 108.59 639.76 64.05 658.36 108.59 631.66 108.59 626.79 119.55 662.69 119.55 677.4 154.63 690.66 154.63 645.84 49.09"/><path fill="#082265" d="M759.63,58.75c-7-6.32-15.81-9.52-26.18-9.52H699.3v105.4h12.44V113.34h0V102.25h0V60.59H734a24.73,24.73,0,0,1,16.22,5.63,18.12,18.12,0,0,1,7.37,14c.39,6.62-1.77,11.88-6.61,16.07a23.43,23.43,0,0,1-16.31,6H721.77v11.09h14.91a33.34,33.34,0,0,0,23.23-8.85,29,29,0,0,0,10-21.91C770,72.89,766.58,64.87,759.63,58.75Z"/><rect fill="#082265" x="296.25" y="51.17" width="12.44" height="12.44"/><rect fill="#082265" x="296.25" y="79.04" width="12.44" height="75.74"/><path fill="#082265" d="M483.63,147.21V114.69a38.6,38.6,0,0,0-12.25-29.2c-8.22-8.22-18.1-12.27-29.35-12a39.17,39.17,0,0,0-27.82,12.54,40.08,40.08,0,0,0-11.29,28.49,41,41,0,0,0,12.24,29.59c8.19,8.18,18,12.12,29.22,11.71a38.78,38.78,0,0,0,27.48-12.33v5.17m0,0c0,6.88-2.73,12.89-8.11,17.88a27.1,27.1,0,0,1-19,7.73,27.83,27.83,0,0,1-16.93-5.64,25.92,25.92,0,0,1-9-10.54l-9.52,5.5a36.63,36.63,0,0,0,9.94,12c6.6,5.25,14.75,8.13,24.23,8.54.59,0,1.18,0,1.77,0a40.89,40.89,0,0,0,26-9.25c8.17-6.52,12.32-14.86,12.32-24.8v-2.95m-12-31.74a29.23,29.23,0,0,1-8.41,20.22,25.68,25.68,0,0,1-19.5,8.38,27.3,27.3,0,0,1-20.2-8.39,28.22,28.22,0,0,1-8.66-20.34,28.66,28.66,0,0,1,7.88-20.61,27.21,27.21,0,0,1,19.53-9.45c.51,0,1,0,1.5,0,7.61,0,14,2.85,19.45,8.69A28.51,28.51,0,0,1,471.59,115.47Z"/><path fill="#082265" d="M274.1,58.75c-7-6.32-15.81-9.52-26.19-9.52H213.76v105.4h12.45V113.34h0V102.25h0V60.59h22.24a24.73,24.73,0,0,1,16.23,5.63,18.12,18.12,0,0,1,7.37,14c.39,6.62-1.77,11.88-6.61,16.07a23.43,23.43,0,0,1-16.31,6H236.24v11.09h14.91a33.34,33.34,0,0,0,23.23-8.85,29,29,0,0,0,10-21.91C284.5,72.89,281.05,64.87,274.1,58.75Z"/><path fill="#082265" d="M357.54,74.41c-9.92,0-18.3,3.43-24.94,10.2s-9.91,15.24-9.91,25.33v44.53h12V108.86a21.82,21.82,0,0,1,6.75-16.1A22.08,22.08,0,0,1,357.54,86a21.49,21.49,0,0,1,15.82,6.75,21.86,21.86,0,0,1,6.89,16.1v45.61h12V109.94c0-10.09-3.34-18.61-9.92-25.33A33.47,33.47,0,0,0,357.54,74.41Z"/></g></g></svg></span><style data-emotion="css 1n4a93h">.css-1n4a93h{display:inherit;margin-right:-4px;margin-left:8px;}.css-1n4a93h&gt;*:nth-of-type(1){font-size:20px;}</style><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-1n4a93h"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="KeyboardArrowDownIcon"><path d="M7.41 8.59 12 13.17l4.59-4.58L18 10l-6 6-6-6 1.41-1.41z"/></svg></span></button></div><style data-emotion="css jnv64h">.css-jnv64h{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;margin-left:auto;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}@media (min-width:0px){.css-jnv64h&gt;:not(style)+:not(style){margin:0;margin-left:8px;}}@media (min-width:1200px){.css-jnv64h&gt;:not(style)+:not(style){margin:0;margin-left:24px;}}</style><div class="css-jnv64h"><style data-emotion="css 1qlh2t1">.css-1qlh2t1{color:#282a36;}</style><div class="MuiBox-root css-1qlh2t1"><style data-emotion="css 1mvsusm">.css-1mvsusm{text-align:center;-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto;font-size:1.5rem;padding:8px;border-radius:50%;overflow:visible;color:rgba(0, 0, 0, 0.54);-webkit-transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;}.css-1mvsusm:hover{background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-1mvsusm:hover{background-color:transparent;}}.css-1mvsusm.Mui-disabled{background-color:transparent;color:rgba(0, 0, 0, 0.26);}@media (min-width:1200px){.css-1mvsusm{;}}</style><style data-emotion="css jwr93t">.css-jwr93t{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;position:relative;box-sizing:border-box;-webkit-tap-highlight-color:transparent;background-color:transparent;outline:0;border:0;margin:0;border-radius:0;padding:0;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;vertical-align:middle;-moz-appearance:none;-webkit-appearance:none;-webkit-text-decoration:none;text-decoration:none;color:inherit;text-align:center;-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto;font-size:1.5rem;padding:8px;border-radius:50%;overflow:visible;color:rgba(0, 0, 0, 0.54);-webkit-transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 150ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;}.css-jwr93t::-moz-focus-inner{border-style:none;}.css-jwr93t.Mui-disabled{pointer-events:none;cursor:default;}@media print{.css-jwr93t{-webkit-print-color-adjust:exact;color-adjust:exact;}}.css-jwr93t:hover{background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-jwr93t:hover{background-color:transparent;}}.css-jwr93t.Mui-disabled{background-color:transparent;color:rgba(0, 0, 0, 0.26);}@media (min-width:1200px){.css-jwr93t{;}}</style><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeMedium css-jwr93t" tabindex="0" type="button"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="LanguageIcon"><path d="M11.99 2C6.47 2 2 6.48 2 12s4.47 10 9.99 10C17.52 22 22 17.52 22 12S17.52 2 11.99 2zm6.93 6h-2.95c-.32-1.25-.78-2.45-1.38-3.56 1.84.63 3.37 1.91 4.33 3.56zM12 4.04c.83 1.2 1.48 2.53 1.91 3.96h-3.82c.43-1.43 1.08-2.76 1.91-3.96zM4.26 14C4.1 13.36 4 12.69 4 12s.1-1.36.26-2h3.38c-.08.66-.14 1.32-.14 2 0 .68.06 1.34.14 2H4.26zm.82 2h2.95c.32 1.25.78 2.45 1.38 3.56-1.84-.63-3.37-1.9-4.33-3.56zm2.95-8H5.08c.96-1.66 2.49-2.93 4.33-3.56C8.81 5.55 8.35 6.75 8.03 8zM12 19.96c-.83-1.2-1.48-2.53-1.91-3.96h3.82c-.43 1.43-1.08 2.76-1.91 3.96zM14.34 14H9.66c-.09-.66-.16-1.32-.16-2 0-.68.07-1.35.16-2h4.68c.09.65.16 1.32.16 2 0 .68-.07 1.34-.16 2zm.25 5.56c.6-1.11 1.06-2.31 1.38-3.56h2.95c-.96 1.65-2.49 2.93-4.33 3.56zM16.36 14c.08-.66.14-1.32.14-2 0-.68-.06-1.34-.14-2h3.38c.16.64.26 1.31.26 2s-.1 1.36-.26 2h-3.38z"/></svg></button><style data-emotion="css t5gsfy">.css-t5gsfy{text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;border-color:currentColor;box-shadow:none;}.css-t5gsfy:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-t5gsfy:hover{background-color:transparent;}}.css-t5gsfy.Mui-disabled{color:rgba(0, 0, 0, 0.26);}.css-t5gsfy:hover{box-shadow:none;}.css-t5gsfy.Mui-focusVisible{box-shadow:none;}.css-t5gsfy:active{box-shadow:none;}.css-t5gsfy.Mui-disabled{box-shadow:none;}@media (min-width:0px){.css-t5gsfy{;}}@media (min-width:1200px){.css-t5gsfy{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;}}</style><style data-emotion="css 1csz7wa">.css-1csz7wa{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;position:relative;box-sizing:border-box;-webkit-tap-highlight-color:transparent;background-color:transparent;outline:0;border:0;margin:0;border-radius:0;padding:0;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;vertical-align:middle;-moz-appearance:none;-webkit-appearance:none;-webkit-text-decoration:none;text-decoration:none;color:inherit;text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:inherit;border-color:currentColor;box-shadow:none;}.css-1csz7wa::-moz-focus-inner{border-style:none;}.css-1csz7wa.Mui-disabled{pointer-events:none;cursor:default;}@media print{.css-1csz7wa{-webkit-print-color-adjust:exact;color-adjust:exact;}}.css-1csz7wa:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-1csz7wa:hover{background-color:transparent;}}.css-1csz7wa.Mui-disabled{color:rgba(0, 0, 0, 0.26);}.css-1csz7wa:hover{box-shadow:none;}.css-1csz7wa.Mui-focusVisible{box-shadow:none;}.css-1csz7wa:active{box-shadow:none;}.css-1csz7wa.Mui-disabled{box-shadow:none;}@media (min-width:0px){.css-1csz7wa{;}}@media (min-width:1200px){.css-1csz7wa{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;}}</style><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textInherit MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-colorInherit MuiButton-disableElevation css-1csz7wa" tabindex="0" type="button" id="header-lang-switch" aria-haspopup="true"><span class="MuiButton-startIcon MuiButton-iconSizeMedium css-6xugel"><style data-emotion="css 1slalk2">.css-1slalk2{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;fill:#282a36;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1slalk2" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="LanguageIcon"><path d="M11.99 2C6.47 2 2 6.48 2 12s4.47 10 9.99 10C17.52 22 22 17.52 22 12S17.52 2 11.99 2zm6.93 6h-2.95c-.32-1.25-.78-2.45-1.38-3.56 1.84.63 3.37 1.91 4.33 3.56zM12 4.04c.83 1.2 1.48 2.53 1.91 3.96h-3.82c.43-1.43 1.08-2.76 1.91-3.96zM4.26 14C4.1 13.36 4 12.69 4 12s.1-1.36.26-2h3.38c-.08.66-.14 1.32-.14 2 0 .68.06 1.34.14 2H4.26zm.82 2h2.95c.32 1.25.78 2.45 1.38 3.56-1.84-.63-3.37-1.9-4.33-3.56zm2.95-8H5.08c.96-1.66 2.49-2.93 4.33-3.56C8.81 5.55 8.35 6.75 8.03 8zM12 19.96c-.83-1.2-1.48-2.53-1.91-3.96h3.82c-.43 1.43-1.08 2.76-1.91 3.96zM14.34 14H9.66c-.09-.66-.16-1.32-.16-2 0-.68.07-1.35.16-2h4.68c.09.65.16 1.32.16 2 0 .68-.07 1.34-.16 2zm.25 5.56c.6-1.11 1.06-2.31 1.38-3.56h2.95c-.96 1.65-2.49 2.93-4.33 3.56zM16.36 14c.08-.66.14-1.32.14-2 0-.68-.06-1.34-.14-2h3.38c.16.64.26 1.31.26 2s-.1 1.36-.26 2h-3.38z"/></svg></span><style data-emotion="css 15r93eu">.css-15r93eu{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;color:inherit;}</style><span class="MuiTypography-root MuiTypography-body1 css-15r93eu">语言</span><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-1n4a93h"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1slalk2" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="KeyboardArrowDownIcon"><path d="M7.41 8.59 12 13.17l4.59-4.58L18 10l-6 6-6-6 1.41-1.41z"/></svg></span></button></div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeMedium css-iuftj9" tabindex="0" type="button"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="SearchIcon"><path d="M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61 0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"/></svg></button><style data-emotion="css ahtg4s">.css-ahtg4s{max-width:13rem;}@media (min-width:0px){.css-ahtg4s{;}}@media (min-width:1200px){.css-ahtg4s{display:block;}}</style><form class="MuiBox-root css-ahtg4s" novalidate="" autocomplete="off"><style data-emotion="css 24u6h2">.css-24u6h2 .MuiOutlinedInput-root:hover fieldset{border-color:#0ca6f2;border-width:1px;}.css-24u6h2 .MuiOutlinedInput-root.Mui-focused fieldset{border-color:#0ca6f2;border-width:1px;}</style><style data-emotion="css fzbqas">.css-fzbqas .MuiOutlinedInput-root:hover fieldset{border-color:#0ca6f2;border-width:1px;}.css-fzbqas .MuiOutlinedInput-root.Mui-focused fieldset{border-color:#0ca6f2;border-width:1px;}</style><style data-emotion="css bj7gct">.css-bj7gct{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;min-width:0;padding:0;margin:0;border:0;vertical-align:top;width:100%;}.css-bj7gct .MuiOutlinedInput-root:hover fieldset{border-color:#0ca6f2;border-width:1px;}.css-bj7gct .MuiOutlinedInput-root.Mui-focused fieldset{border-color:#0ca6f2;border-width:1px;}</style><div class="MuiFormControl-root MuiFormControl-fullWidth MuiTextField-root css-bj7gct"><style data-emotion="css-global 1prfaxn">@-webkit-keyframes mui-auto-fill{from{display:block;}}@keyframes mui-auto-fill{from{display:block;}}@-webkit-keyframes mui-auto-fill-cancel{from{display:block;}}@keyframes mui-auto-fill-cancel{from{display:block;}}</style><style data-emotion="css sv5gtw">.css-sv5gtw{font-size:1rem;line-height:1.4375em;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:rgba(0, 0, 0, 0.87);box-sizing:border-box;position:relative;cursor:text;display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;width:100%;position:relative;border-radius:4px;padding-left:14px;background:#fff;}.css-sv5gtw.Mui-disabled{color:rgba(0, 0, 0, 0.38);cursor:default;}.css-sv5gtw:hover .MuiOutlinedInput-notchedOutline{border-color:rgba(0, 0, 0, 0.87);}@media (hover: none){.css-sv5gtw:hover .MuiOutlinedInput-notchedOutline{border-color:rgba(0, 0, 0, 0.23);}}.css-sv5gtw.Mui-focused .MuiOutlinedInput-notchedOutline{border-color:#1976d2;border-width:2px;}.css-sv5gtw.Mui-error .MuiOutlinedInput-notchedOutline{border-color:#d32f2f;}.css-sv5gtw.Mui-disabled .MuiOutlinedInput-notchedOutline{border-color:rgba(0, 0, 0, 0.26);}</style><div class="MuiInputBase-root MuiOutlinedInput-root MuiInputBase-colorPrimary MuiInputBase-fullWidth MuiInputBase-formControl MuiInputBase-sizeSmall MuiInputBase-adornedStart css-sv5gtw"><style data-emotion="css 1a6giau">.css-1a6giau{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;height:0.01em;max-height:2em;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;white-space:nowrap;color:rgba(0, 0, 0, 0.54);margin-right:8px;}</style><div class="MuiInputAdornment-root MuiInputAdornment-positionStart MuiInputAdornment-outlined MuiInputAdornment-sizeSmall css-1a6giau"><span class="notranslate"></span><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="SearchIcon"><path d="M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61 0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"/></svg></div><style data-emotion="css f2zrvi">.css-f2zrvi{font:inherit;letter-spacing:inherit;color:currentColor;padding:4px 0 5px;border:0;box-sizing:content-box;background:none;height:1.4375em;margin:0;-webkit-tap-highlight-color:transparent;display:block;min-width:0;width:100%;-webkit-animation-name:mui-auto-fill-cancel;animation-name:mui-auto-fill-cancel;-webkit-animation-duration:10ms;animation-duration:10ms;padding-top:1px;-moz-appearance:textfield;padding:8.5px 14px;padding-left:0;}.css-f2zrvi::-webkit-input-placeholder{color:currentColor;opacity:0.42;-webkit-transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-f2zrvi::-moz-placeholder{color:currentColor;opacity:0.42;-webkit-transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-f2zrvi:-ms-input-placeholder{color:currentColor;opacity:0.42;-webkit-transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-f2zrvi::-ms-input-placeholder{color:currentColor;opacity:0.42;-webkit-transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:opacity 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;}.css-f2zrvi:focus{outline:0;}.css-f2zrvi:invalid{box-shadow:none;}.css-f2zrvi::-webkit-search-decoration{-webkit-appearance:none;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi::-webkit-input-placeholder{opacity:0!important;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi::-moz-placeholder{opacity:0!important;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi:-ms-input-placeholder{opacity:0!important;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi::-ms-input-placeholder{opacity:0!important;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi:focus::-webkit-input-placeholder{opacity:0.42;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi:focus::-moz-placeholder{opacity:0.42;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi:focus:-ms-input-placeholder{opacity:0.42;}label[data-shrink=false]+.MuiInputBase-formControl .css-f2zrvi:focus::-ms-input-placeholder{opacity:0.42;}.css-f2zrvi.Mui-disabled{opacity:1;-webkit-text-fill-color:rgba(0, 0, 0, 0.38);}.css-f2zrvi:-webkit-autofill{-webkit-animation-duration:5000s;animation-duration:5000s;-webkit-animation-name:mui-auto-fill;animation-name:mui-auto-fill;}.css-f2zrvi:-webkit-autofill{border-radius:inherit;}</style><input type="search" aria-invalid="false" id="doc-search" placeholder="搜索文档" value="" class="MuiInputBase-input MuiOutlinedInput-input MuiInputBase-inputTypeSearch MuiInputBase-inputSizeSmall MuiInputBase-inputAdornedStart css-f2zrvi"/><style data-emotion="css 19w1uun">.css-19w1uun{border-color:rgba(0, 0, 0, 0.23);}</style><style data-emotion="css igs3ac">.css-igs3ac{text-align:left;bottom:0;right:0;top:-5px;left:0;margin:0;padding:0 8px;pointer-events:none;border-radius:inherit;border-style:solid;border-width:1px;overflow:hidden;min-width:0%;border-color:rgba(0, 0, 0, 0.23);}</style><fieldset aria-hidden="true" class="MuiOutlinedInput-notchedOutline css-igs3ac"><style data-emotion="css hdw1oc">.css-hdw1oc{float:unset;overflow:hidden;padding:0;line-height:11px;-webkit-transition:width 150ms cubic-bezier(0.0, 0, 0.2, 1) 0ms;transition:width 150ms cubic-bezier(0.0, 0, 0.2, 1) 0ms;}</style><legend class="css-hdw1oc"><span class="notranslate"></span></legend></fieldset></div></div></form></div></div></header><style data-emotion="css s1brf2">.css-s1brf2{margin-top:5rem;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;}</style><div class="PingCAP-Doc MuiBox-root css-s1brf2"><style data-emotion="css hboir5">.css-hboir5{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;width:100%;}</style><div class="MuiBox-root css-hboir5"><style data-emotion="css 2tzg8">.css-2tzg8{width:18.75rem;border-right:1px solid #E5E4E4;}@media (min-width:0px){.css-2tzg8{;}}@media (min-width:1200px){.css-2tzg8{display:block;}}</style><aside class="MuiBox-root css-2tzg8"><style data-emotion="css 1eohm8p">.css-1eohm8p{position:-webkit-sticky;position:sticky;top:5rem;height:100%;max-height:calc(100vh - 7rem);overflow-y:auto;padding:1rem;}</style><div class="MuiBox-root css-1eohm8p"><style data-emotion="css fmyu0n">.css-fmyu0n{text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:#1976d2;width:100%;height:2rem;-webkit-box-pack:justify;-webkit-justify-content:space-between;justify-content:space-between;border-style:solid;border-width:1px;border-color:#e5e5e5;margin-bottom:1rem;}.css-fmyu0n:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(25, 118, 210, 0.04);}@media (hover: none){.css-fmyu0n:hover{background-color:transparent;}}.css-fmyu0n.Mui-disabled{color:rgba(0, 0, 0, 0.26);}</style><style data-emotion="css 1rq233s">.css-1rq233s{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;position:relative;box-sizing:border-box;-webkit-tap-highlight-color:transparent;background-color:transparent;outline:0;border:0;margin:0;border-radius:0;padding:0;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;vertical-align:middle;-moz-appearance:none;-webkit-appearance:none;-webkit-text-decoration:none;text-decoration:none;color:inherit;text-transform:none;font-family:-apple-system,"Poppins","Helvetica Neue",sans-serif,"Noto Sans","Fira Code","IBM Plex Sans","sans-serif";font-weight:500;font-size:0.875rem;line-height:1.75;min-width:64px;padding:6px 8px;border-radius:4px;-webkit-transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:background-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,box-shadow 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,border-color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms,color 250ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;color:#1976d2;width:100%;height:2rem;-webkit-box-pack:justify;-webkit-justify-content:space-between;justify-content:space-between;border-style:solid;border-width:1px;border-color:#e5e5e5;margin-bottom:1rem;}.css-1rq233s::-moz-focus-inner{border-style:none;}.css-1rq233s.Mui-disabled{pointer-events:none;cursor:default;}@media print{.css-1rq233s{-webkit-print-color-adjust:exact;color-adjust:exact;}}.css-1rq233s:hover{-webkit-text-decoration:none;text-decoration:none;background-color:rgba(25, 118, 210, 0.04);}@media (hover: none){.css-1rq233s:hover{background-color:transparent;}}.css-1rq233s.Mui-disabled{color:rgba(0, 0, 0, 0.26);}</style><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textPrimary MuiButton-sizeMedium MuiButton-textSizeMedium css-1rq233s" tabindex="0" type="button" id="version-select-button" aria-haspopup="true"><style data-emotion="css 3cb5vr">.css-3cb5vr{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;padding:0 0.25rem;font-size:0.875rem;line-height:1.25rem;}</style><div class="MuiTypography-root MuiTypography-body1 css-3cb5vr">v7.1</div><style data-emotion="css 1n4a93h">.css-1n4a93h{display:inherit;margin-right:-4px;margin-left:8px;}.css-1n4a93h&gt;*:nth-of-type(1){font-size:20px;}</style><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-1n4a93h"><style data-emotion="css b5l66">.css-b5l66{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;-webkit-transform:rotate(0deg);-moz-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);height:1.5rem;width:1.5rem;fill:#999999;margin-right:0.25rem;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-b5l66" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></span></button><style data-emotion="css 1c58svf">.css-1c58svf .MuiPaper-root{border-radius:6px;margin-top:8px;min-width:268px;color:rgb(55, 65, 81);box-shadow:rgb(255, 255, 255) 0px 0px 0px 0px,rgba(0, 0, 0, 0.05) 0px 0px 0px 1px,rgba(0, 0, 0, 0.1) 0px 10px 15px -3px,rgba(0, 0, 0, 0.05) 0px 4px 6px -2px;}.css-1c58svf .MuiPaper-root .MuiMenu-list{padding:4px 0;}.css-1c58svf .MuiPaper-root .MuiMenuItem-root .MuiSvgIcon-root{font-size:18px;color:rgba(0, 0, 0, 0.6);margin-right:12px;}.css-1c58svf .MuiPaper-root .MuiMenuItem-root:active{background-color:rgba(25, 118, 210, 0.08);}</style><style data-emotion="css yvxbj">.css-yvxbj .MuiPaper-root{border-radius:6px;margin-top:8px;min-width:268px;color:rgb(55, 65, 81);box-shadow:rgb(255, 255, 255) 0px 0px 0px 0px,rgba(0, 0, 0, 0.05) 0px 0px 0px 1px,rgba(0, 0, 0, 0.1) 0px 10px 15px -3px,rgba(0, 0, 0, 0.05) 0px 4px 6px -2px;}.css-yvxbj .MuiPaper-root .MuiMenu-list{padding:4px 0;}.css-yvxbj .MuiPaper-root .MuiMenuItem-root .MuiSvgIcon-root{font-size:18px;color:rgba(0, 0, 0, 0.6);margin-right:12px;}.css-yvxbj .MuiPaper-root .MuiMenuItem-root:active{background-color:rgba(25, 118, 210, 0.08);}</style><style data-emotion="css oe3wem">.css-oe3wem .MuiPaper-root{border-radius:6px;margin-top:8px;min-width:268px;color:rgb(55, 65, 81);box-shadow:rgb(255, 255, 255) 0px 0px 0px 0px,rgba(0, 0, 0, 0.05) 0px 0px 0px 1px,rgba(0, 0, 0, 0.1) 0px 10px 15px -3px,rgba(0, 0, 0, 0.05) 0px 4px 6px -2px;}.css-oe3wem .MuiPaper-root .MuiMenu-list{padding:4px 0;}.css-oe3wem .MuiPaper-root .MuiMenuItem-root .MuiSvgIcon-root{font-size:18px;color:rgba(0, 0, 0, 0.6);margin-right:12px;}.css-oe3wem .MuiPaper-root .MuiMenuItem-root:active{background-color:rgba(25, 118, 210, 0.08);}</style><style data-emotion="css 12mehxg">.css-12mehxg{padding:0;margin:0;list-style:none;outline:0;}</style><ul role="tree" id="left-nav-treeview" aria-multiselectable="false" class="MuiTreeView-root css-12mehxg" tabindex="0" aria-label="left navigation"><style data-emotion="css 1gesgke">.css-1gesgke .MuiTreeItem-content{color:#282a36;border-radius:4px;}.css-1gesgke .MuiTreeItem-content:hover{background-color:#f9f9f9;}.css-1gesgke .MuiTreeItem-content.Mui-selected,.css-1gesgke .MuiTreeItem-content.Mui-selected.Mui-focused{background-color:var(--tree-view-bg-color, #EAF6FB);color:var(--tree-view-color, #0A85C2);}.css-1gesgke .MuiTreeItem-content.Mui-selected svg.MuiTreeItem-ChevronRightIcon,.css-1gesgke .MuiTreeItem-content.Mui-selected.Mui-focused svg.MuiTreeItem-ChevronRightIcon{fill:var(--tree-view-color, #0A85C2);}.css-1gesgke .MuiTreeItem-content.Mui-focused{background-color:#f9f9f9;}.css-1gesgke .MuiTreeItem-content .MuiTreeItem-label{font-weight:inherit;color:inherit;}.css-1gesgke .MuiTreeItem-content .MuiTreeItem-iconContainer{;}.css-1gesgke .MuiTreeItem-group{margin-left:0;}.css-1gesgke .MuiTreeItem-group .MuiTreeItem-content{padding-left:16px;}</style><style data-emotion="css 1oy5rnm">.css-1oy5rnm{list-style:none;margin:0;padding:0;outline:0;}.css-1oy5rnm .MuiTreeItem-content{color:#282a36;border-radius:4px;}.css-1oy5rnm .MuiTreeItem-content:hover{background-color:#f9f9f9;}.css-1oy5rnm .MuiTreeItem-content.Mui-selected,.css-1oy5rnm .MuiTreeItem-content.Mui-selected.Mui-focused{background-color:var(--tree-view-bg-color, #EAF6FB);color:var(--tree-view-color, #0A85C2);}.css-1oy5rnm .MuiTreeItem-content.Mui-selected svg.MuiTreeItem-ChevronRightIcon,.css-1oy5rnm .MuiTreeItem-content.Mui-selected.Mui-focused svg.MuiTreeItem-ChevronRightIcon{fill:var(--tree-view-color, #0A85C2);}.css-1oy5rnm .MuiTreeItem-content.Mui-focused{background-color:#f9f9f9;}.css-1oy5rnm .MuiTreeItem-content .MuiTreeItem-label{font-weight:inherit;color:inherit;}.css-1oy5rnm .MuiTreeItem-content .MuiTreeItem-iconContainer{;}.css-1oy5rnm .MuiTreeItem-group{margin-left:0;}.css-1oy5rnm .MuiTreeItem-group .MuiTreeItem-content{padding-left:16px;}</style><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><style data-emotion="css khel7y">.css-khel7y{padding:0 8px;width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;cursor:pointer;-webkit-tap-highlight-color:transparent;}.css-khel7y:hover{background-color:rgba(0, 0, 0, 0.04);}@media (hover: none){.css-khel7y:hover{background-color:transparent;}}.css-khel7y.Mui-disabled{opacity:0.38;background-color:transparent;}.css-khel7y.Mui-focused{background-color:rgba(0, 0, 0, 0.12);}.css-khel7y.Mui-selected{background-color:rgba(25, 118, 210, 0.08);}.css-khel7y.Mui-selected:hover{background-color:rgba(25, 118, 210, 0.12);}@media (hover: none){.css-khel7y.Mui-selected:hover{background-color:rgba(25, 118, 210, 0.08);}}.css-khel7y.Mui-selected.Mui-focused{background-color:rgba(25, 118, 210, 0.2);}.css-khel7y .MuiTreeItem-iconContainer{margin-right:4px;width:15px;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;}.css-khel7y .MuiTreeItem-iconContainer svg{font-size:18px;}.css-khel7y .MuiTreeItem-label{width:100%;min-width:0;padding-left:4px;position:relative;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;}</style><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><style data-emotion="css znl8a3">.css-znl8a3{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;min-height:1.75rem;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-left:0rem;padding-top:0.25rem;padding-bottom:0.25rem;}</style><div class="css-znl8a3"><style data-emotion="css tx8jsd">.css-tx8jsd{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;}</style><a class="MuiTypography-root MuiTypography-body1 css-tx8jsd" target="_blank" href="https://docs.pingcap.com/zh" style="text-decoration:none;width:100%;color:inherit"><style data-emotion="css 8atqhb">.css-8atqhb{width:100%;}</style><div class="MuiBox-root css-8atqhb"><style data-emotion="css 1hwyipb">.css-1hwyipb{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;color:inherit;font-size:0.875rem;line-height:1.25rem;}</style><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">文档中心</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">关于 TiDB</div></div><style data-emotion="css xjq79n">.css-xjq79n{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;fill:#999999;height:1rem;width:1rem;margin-left:auto;-webkit-transform:none;-moz-transform:none;-ms-transform:none;transform:none;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div><style data-emotion="css 1jozaee">.css-1jozaee{margin:0;padding:0;margin-left:17px;}</style></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">快速上手</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">应用开发</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">部署标准集群</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">数据迁移</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">数据集成</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">运维操作</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">监控与告警</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">故障诊断</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">性能调优</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">教程</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">TiDB 工具</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-13" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">参考指南</div></div><style data-emotion="css 171pefp">.css-171pefp{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:1.5rem;fill:#999999;height:1rem;width:1rem;margin-left:auto;-webkit-transform:rotate(90deg);-moz-transform:rotate(90deg);-ms-transform:rotate(90deg);transform:rotate(90deg);}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-171pefp" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div><style data-emotion="css 1xxsnna">.css-1xxsnna{height:auto;overflow:visible;-webkit-transition:height 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:height 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;margin:0;padding:0;margin-left:17px;}</style><ul class="MuiCollapse-root MuiCollapse-vertical MuiTreeItem-group MuiCollapse-entered css-1xxsnna" style="min-height:0px" role="group"><div class="MuiCollapse-wrapper MuiCollapse-vertical css-hboir5"><div class="MuiCollapse-wrapperInner MuiCollapse-vertical css-8atqhb"><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><style data-emotion="css kb2j4b">.css-kb2j4b{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;min-height:1.75rem;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-left:0.5rem;padding-top:0.25rem;padding-bottom:0.25rem;}</style><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">架构</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">存储引擎 TiKV</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">存储引擎 TiFlash</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/system-variables"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">系统变量</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">配置文件参数</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">CLI</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">命令行参数</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">监控指标</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">安全加固</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">权限</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-13-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">SQL</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-171pefp" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div><ul class="MuiCollapse-root MuiCollapse-vertical MuiTreeItem-group MuiCollapse-entered css-1xxsnna" style="min-height:0px" role="group"><div class="MuiCollapse-wrapper MuiCollapse-vertical css-hboir5"><div class="MuiCollapse-wrapperInner MuiCollapse-vertical css-8atqhb"><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><style data-emotion="css snygwd">.css-snygwd{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;min-height:1.75rem;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-left:1rem;padding-top:0.25rem;padding-bottom:0.25rem;}</style><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">SQL 语言结构和语法</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">SQL 语句</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">数据类型</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-13-10-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">函数与操作符</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-171pefp" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div><ul class="MuiCollapse-root MuiCollapse-vertical MuiTreeItem-group MuiCollapse-entered css-1xxsnna" style="min-height:0px" role="group"><div class="MuiCollapse-wrapper MuiCollapse-vertical css-hboir5"><div class="MuiCollapse-wrapperInner MuiCollapse-vertical css-8atqhb"><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><style data-emotion="css 5fc025">.css-5fc025{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;min-height:1.75rem;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;padding-left:1.5rem;padding-top:0.25rem;padding-bottom:0.25rem;}</style><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/functions-and-operators-overview"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">函数与操作符概述</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/type-conversion-in-expression-evaluation"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">表达式求值的类型转换</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/operators"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">操作符</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/control-flow-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">控制流程函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/string-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">字符串函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/numeric-functions-and-operators"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">数值函数与操作符</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/date-and-time-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">日期和时间函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/bit-functions-and-operators"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">位函数和操作符</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/cast-functions-and-operators"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">Cast 函数和操作符</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/encryption-and-compression-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">加密和压缩函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/locking-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">锁函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/information-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">信息函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/json-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">JSON 函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-13" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/aggregate-group-by-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">GROUP BY 聚合函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-14" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/window-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">窗口函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-15" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/miscellaneous-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">其它函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-16" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/precision-math"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">精度数学</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-17" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/set-operators"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">集合运算</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-18" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/expressions-pushed-down"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">下推到 TiKV 的表达式列表</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-19" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a aria-current="page" style="text-decoration:none;width:100%;color:inherit" class="" href="/zh/tidb/stable/tidb-functions"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">TiDB 特有的函数</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-3-20" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-5fc025"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/oracle-functions-to-tidb"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">Oracle 与 TiDB 函数和语法差异对照</div></div></a></div></div></div></li></div></div></ul></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/clustered-indexes"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">聚簇索引</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/constraints"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">约束</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/generated-columns"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">生成列</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/sql-mode"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">SQL 模式</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/table-attributes"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">表属性</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">事务</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/views"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">视图</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/partitioned-table"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">分区表</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/temporary-tables"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">临时表</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-13" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/cached-tables"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">缓存表</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-14" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/foreign-key"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">外键约束</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-15" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">字符集和排序</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-16" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/placement-rules-in-sql"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">Placement Rules in SQL</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-10-17" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">系统表</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-10-18" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-snygwd"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/metadata-lock"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">元数据锁</div></div></a></div></div></div></li></div></div></ul></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">UI</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/telemetry"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">遥测</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-13" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/error-codes"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">错误码</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-13-14" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/schedule-replicas-by-topology-labels"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">通过拓扑 label 进行副本调度</div></div></a></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13-15" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-kb2j4b"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">内部组件介绍</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li></div></div></ul></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-14" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">常见问题解答 (FAQ)</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-15" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">版本发布历史</div></div><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-xjq79n" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></div></div></div></li><li class="MuiTreeItem-root css-1oy5rnm" role="treeitem" id="left-nav-treeview-0-16" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-khel7y MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-znl8a3"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/glossary"><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1hwyipb">术语表</div></div></a></div></div></div></li></ul></div></aside><style data-emotion="css sb2sd0">.css-sb2sd0{width:100%;}@media (min-width:1200px){.css-sb2sd0{max-width:calc(100% - 18.75rem);}}</style><main class="MuiBox-root css-sb2sd0"><style data-emotion="css 1rnnmjb">.css-1rnnmjb{max-width:1340px;width:100%;margin-left:auto;margin-right:auto;display:block;box-sizing:border-box;}</style><div class="MuiBox-root css-1rnnmjb"><style data-emotion="css 90fn5w">.css-90fn5w{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;}@media (min-width:0px){.css-90fn5w{-webkit-flex-direction:column-reverse;-ms-flex-direction:column-reverse;flex-direction:column-reverse;}}@media (min-width:600px){.css-90fn5w{-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;}}</style><div class="css-90fn5w"><style data-emotion="css vofosd">.css-vofosd{padding:1.5rem 0;}@media (min-width:0px){.css-vofosd{width:100%;}}@media (min-width:600px){.css-vofosd{width:calc(100% - 17.5rem);}}</style><div class="MuiBox-root css-vofosd"><style data-emotion="css 1ekb41w">.css-1ekb41w{width:100%;margin-left:auto;box-sizing:border-box;margin-right:auto;display:block;padding-left:16px;padding-right:16px;}@media (min-width:600px){.css-1ekb41w{padding-left:24px;padding-right:24px;}}@media (min-width:1536px){.css-1ekb41w{max-width:1536px;}}</style><div class="MuiContainer-root MuiContainer-maxWidthXl doc-content css-1ekb41w"><div class="markdown-body MuiBox-root css-0"><h1 id="tidb-特有的函数" style="position:relative"><a href="#tidb-%E7%89%B9%E6%9C%89%E7%9A%84%E5%87%BD%E6%95%B0" aria-label="tidb 特有的函数 permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TiDB 特有的函数</h1><p>以下函数为 TiDB 中特有的函数，与 MySQL 不兼容：</p><table><thead><tr><th align="left">函数名</th><th align="left">函数说明</th></tr></thead><tbody><tr><td align="left"><code>TIDB_BOUNDED_STALENESS()</code></td><td align="left"><code>TIDB_BOUNDED_STALENESS</code> 函数指示 TiDB 在指定时间范围内读取尽可能新的数据。参见<a href="/zh/tidb/stable/as-of-timestamp">使用 AS OF TIMESTAMP 语法读取历史数据</a>。</td></tr><tr><td align="left"><a href="#tidb_decode_key"><code>TIDB_DECODE_KEY(str)</code></a></td><td align="left"><code>TIDB_DECODE_KEY</code> 函数用于将 TiDB 编码的键输入解码为包含 <code>_tidb_rowid</code> 和 <code>table_id</code> 的 JSON 结构。你可以在一些系统表和日志输出中找到 TiDB 的编码键。</td></tr><tr><td align="left"><a href="#tidb_decode_plan"><code>TIDB_DECODE_PLAN(str)</code></a></td><td align="left"><code>TIDB_DECODE_PLAN</code> 函数用于解码 TiDB 执行计划。</td></tr><tr><td align="left"><code>TIDB_IS_DDL_OWNER()</code></td><td align="left"><code>TIDB_IS_DDL_OWNER</code> 函数用于检查你连接的 TiDB 实例是否是 DDL Owner。DDL Owner 代表集群中所有其他节点执行 DDL 语句的 TiDB 实例。</td></tr><tr><td align="left"><a href="#tidb_parse_tso"><code>TIDB_PARSE_TSO(num)</code></a></td><td align="left"><code>TIDB_PARSE_TSO</code> 函数用于从 TiDB TSO 时间戳中提取物理时间戳。参见 <a href="/zh/tidb/stable/system-variables#tidb_current_ts"><code>tidb_current_ts</code></a>。</td></tr><tr><td align="left"><a href="#tidb_version"><code>TIDB_VERSION()</code></a></td><td align="left"><code>TIDB_VERSION</code> 函数用于获取当前连接的 TiDB 服务器版本和构建详细信息。</td></tr><tr><td align="left"><a href="#tidb_decode_sql_digests"><code>TIDB_DECODE_SQL_DIGESTS(digests, stmtTruncateLength)</code></a></td><td align="left"><code>TIDB_DECODE_SQL_DIGESTS</code> 函数用于在集群中查询一组 SQL Digest 所对应的 SQL 语句的归一化形式（即去除格式和参数后的形式）。</td></tr><tr><td align="left"><code>VITESS_HASH(str)</code></td><td align="left"><code>VITESS_HASH</code> 函数返回与 Vitess 的 <code>HASH</code> 函数兼容的字符串哈希值，有助于从 Vitess 迁移数据。</td></tr><tr><td align="left"><code>TIDB_SHARD()</code></td><td align="left"><code>TIDB_SHARD</code> 函数用于创建一个 SHARD INDEX 来打散热点索引。SHARD INDEX 是一种以 <code>TIDB_SHARD</code> 函数为前缀的表达式索引。</td></tr><tr><td align="left"><code>TIDB_ROW_CHECKSUM()</code></td><td align="left"><code>TIDB_ROW_CHECKSUM()</code> 函数用于查询行数据的 Checksum 值。该函数只能用于 FastPlan 流程的 <code>SELECT</code> 语句，即你可通过形如 <code>SELECT TIDB_ROW_CHECKSUM() FROM t WHERE id = ?</code> 或 <code>SELECT TIDB_ROW_CHECKSUM() FROM t WHERE id IN (?, ?, ...)</code> 的语句进行查询。参见<a href="/zh/tidb/stable/ticdc-integrity-check">数据正确性校验</a>。</td></tr><tr><td align="left"><code>CURRENT_RESOURCE_GROUP()</code></td><td align="left"><code>CURRENT_RESOURCE_GROUP()</code> 用于查询当前连接绑定的资源组名。参见<a href="/zh/tidb/stable/tidb-resource-control">使用资源管控 (Resource Control) 实现资源隔离</a>。</td></tr></tbody></table><h2 id="示例" style="position:relative"><a href="#%E7%A4%BA%E4%BE%8B" aria-label="示例 permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>示例</h2><p>下面为部分以上函数的示例。</p><h3 id="tidb_decode_key" style="position:relative"><a href="#tidb_decode_key" aria-label="tidb_decode_key permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_DECODE_KEY</h3><p><code>TIDB_DECODE_KEY</code> 函数用于将 TiDB 编码的键输入解码为包含 <code>_tidb_rowid</code> 和 <code>table_id</code> 的 JSON 结构。你可以在一些系统表和日志输出中找到 TiDB 的编码键。</p><p>以下示例中，表 <code>t1</code> 有一个隐藏的 <code>rowid</code>，该 <code>rowid</code> 由 TiDB 生成。语句中使用了 <code>TIDB_DECODE_KEY</code> 函数。结果显示，隐藏的 <code>rowid</code> 被解码后并输出，这是典型的非聚簇主键结果。</p><pre><code class="language-sql">SELECT START_KEY, TIDB_DECODE_KEY(START_KEY) FROM information_schema.tikv_region_status WHERE table_name='t1' AND REGION_ID=2\G </code></pre><pre><code class="language-sql">*************************** 1. row *************************** START_KEY: 7480000000000000FF3B5F728000000000FF1DE3F10000000000FA TIDB_DECODE_KEY(START_KEY): {"_tidb_rowid":1958897,"table_id":"59"} 1 row in set (0.00 sec) </code></pre><p>以下示例中，表 <code>t2</code> 有一个复合聚簇主键。由 JSON 输出可知，输出结果的 <code>handle</code> 项中包含了主键部分两列的信息，即两列的名称和对应的值。</p><pre><code class="language-sql">show create table t2\G </code></pre><pre><code class="language-sql">*************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` binary(36) NOT NULL, `a` tinyint(3) unsigned NOT NULL, `v` varchar(512) DEFAULT NULL, PRIMARY KEY (`a`,`id`) /*T![clustered_index] CLUSTERED */ ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin 1 row in set (0.001 sec) </code></pre><pre><code class="language-sql">select * from information_schema.tikv_region_status where table_name='t2' limit 1\G </code></pre><pre><code class="language-sql">*************************** 1. row *************************** REGION_ID: 48 START_KEY: 7480000000000000FF3E5F720400000000FF0000000601633430FF3338646232FF2D64FF3531632D3131FF65FF622D386337352DFFFF3830653635303138FFFF61396265000000FF00FB000000000000F9 END_KEY: TABLE_ID: 62 DB_NAME: test TABLE_NAME: t2 IS_INDEX: 0 INDEX_ID: NULL INDEX_NAME: NULL EPOCH_CONF_VER: 1 EPOCH_VERSION: 38 WRITTEN_BYTES: 0 READ_BYTES: 0 APPROXIMATE_SIZE: 136 APPROXIMATE_KEYS: 479905 REPLICATIONSTATUS_STATE: NULL REPLICATIONSTATUS_STATEID: NULL 1 row in set (0.005 sec) </code></pre><pre><code class="language-sql">select tidb_decode_key('7480000000000000FF3E5F720400000000FF0000000601633430FF3338646232FF2D64FF3531632D3131FF65FF622D386337352DFFFF3830653635303138FFFF61396265000000FF00FB000000000000F9'); </code></pre><pre><code class="language-sql">+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | tidb_decode_key('7480000000000000FF3E5F720400000000FF0000000601633430FF3338646232FF2D64FF3531632D3131FF65FF622D386337352DFFFF3830653635303138FFFF61396265000000FF00FB000000000000F9') | +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | {"handle":{"a":"6","id":"c4038db2-d51c-11eb-8c75-80e65018a9be"},"table_id":62} | +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.001 sec) </code></pre><h3 id="tidb_decode_plan" style="position:relative"><a href="#tidb_decode_plan" aria-label="tidb_decode_plan permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_DECODE_PLAN</h3><p>你可以在慢查询日志中找到编码形式的 TiDB 执行计划，然后使用 <code>TIDB_DECODE_PLAN()</code> 函数将编码的执行计划解码为易读的形式。</p><p>该函数很有用，因为在执行语句时 TiDB 会捕获执行计划。重新执行 <code>EXPLAIN</code> 中的语句可能会产生不同的结果，因为数据分布和统计数据会随着时间的推移而变化。</p><pre><code class="language-sql">SELECT tidb_decode_plan('8QIYMAkzMV83CQEH8E85LjA0CWRhdGE6U2VsZWN0aW9uXzYJOTYwCXRpbWU6NzEzLjHCtXMsIGxvb3BzOjIsIGNvcF90YXNrOiB7bnVtOiAxLCBtYXg6IDU2OC41wgErRHByb2Nfa2V5czogMCwgcnBjXxEpAQwFWBAgNTQ5LglZyGNvcHJfY2FjaGVfaGl0X3JhdGlvOiAwLjAwfQkzLjk5IEtCCU4vQQoxCTFfNgkxXzAJMwm2SGx0KHRlc3QudC5hLCAxMDAwMCkNuQRrdgmiAHsFbBQzMTMuOMIBmQnEDDk2MH0BUgEEGAoyCTQzXzUFVwX1oGFibGU6dCwga2VlcCBvcmRlcjpmYWxzZSwgc3RhdHM6cHNldWRvCTk2ISE2aAAIMTUzXmYA')\G </code></pre><pre><code class="language-sql">*************************** 1. row *************************** tidb_decode_plan('8QIYMAkzMV83CQEH8E85LjA0CWRhdGE6U2VsZWN0aW9uXzYJOTYwCXRpbWU6NzEzLjHCtXMsIGxvb3BzOjIsIGNvcF90YXNrOiB7bnVtOiAxLCBtYXg6IDU2OC41wgErRHByb2Nfa2V5czogMCwgcnBjXxEpAQwFWBAgNTQ5LglZyGNvcHJfY2FjaGVfaGl0X3JhdGlvOiAwLjAwfQkzLjk5IEtCCU4vQQoxCTFfNgkxXz: id task estRows operator info actRows execution info memory disk TableReader_7 root 319.04 data:Selection_6 960 time:713.1µs, loops:2, cop_task: {num: 1, max: 568.5µs, proc_keys: 0, rpc_num: 1, rpc_time: 549.1µs, copr_cache_hit_ratio: 0.00} 3.99 KB N/A └─Selection_6 cop[tikv] 319.04 lt(test.t.a, 10000) 960 tikv_task:{time:313.8µs, loops:960} N/A N/A └─TableFullScan_5 cop[tikv] 960 table:t, keep order:false, stats:pseudo 960 tikv_task:{time:153µs, loops:960} N/A N/A </code></pre><h3 id="tidb_parse_tso" style="position:relative"><a href="#tidb_parse_tso" aria-label="tidb_parse_tso permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_PARSE_TSO</h3><p><code>TIDB_PARSE_TSO</code> 函数用于从 TiDB TSO 时间戳中提取物理时间戳。</p><p>TSO 指 Time Stamp Oracle，是 PD (Placement Driver) 为每个事务提供的单调递增的时间戳。TSO 是一串数字，包含以下两部分：</p><ul><li>一个物理时间戳</li><li>一个逻辑计数器</li></ul><pre><code class="language-sql">BEGIN; SELECT TIDB_PARSE_TSO(@@tidb_current_ts); ROLLBACK; </code></pre><pre><code class="language-sql">+-----------------------------------+ | TIDB_PARSE_TSO(@@tidb_current_ts) | +-----------------------------------+ | 2021-05-26 11:33:37.776000 | +-----------------------------------+ 1 row in set (0.0012 sec) </code></pre><p>以上示例使用 <code>TIDB_PARSE_TSO</code> 函数从 <code>tidb_current_ts</code> 会话变量提供的可用时间戳编号中提取物理时间戳。因为每个事务都会分配到时间戳，所以此函数在事务中运行。</p><h3 id="tidb_version" style="position:relative"><a href="#tidb_version" aria-label="tidb_version permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_VERSION</h3><p><code>TIDB_VERSION</code> 函数用于获取当前连接的 TiDB 服务器版本和构建详细信息。向 GitHub 上提交 issue 时，你可使用此函数获取相关信息。</p><pre><code class="language-sql">SELECT TIDB_VERSION()\G </code></pre><pre><code class="language-sql">*************************** 1. row *************************** TIDB_VERSION(): Release Version: v5.1.0-alpha-13-gd5e0ed0aa-dirty Edition: Community Git Commit Hash: d5e0ed0aaed72d2f2dfe24e9deec31cb6cb5fdf0 Git Branch: master UTC Build Time: 2021-05-24 14:39:20 GoVersion: go1.13 Race Enabled: false TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306 Check Table Before Drop: false 1 row in set (0.00 sec) </code></pre><h3 id="tidb_decode_sql_digests" style="position:relative"><a href="#tidb_decode_sql_digests" aria-label="tidb_decode_sql_digests permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_DECODE_SQL_DIGESTS</h3><p><code>TIDB_DECODE_SQL_DIGESTS()</code> 函数用于在集群中查询一组 SQL Digest 所对应的 SQL 语句的归一化形式（即去除格式和参数后的形式）。函数接受 1 个或 2 个参数：</p><ul><li><code>digests</code>：字符串类型，该参数应符合 JSON 字符串数组的格式，数组中的每个字符串应为一个 SQL Digest。</li><li><code>stmtTruncateLength</code>：可选参数，整数类型，用来限制返回结果中每条 SQL 语句的长度，超过指定的长度会被截断。0 表示不限制长度。</li></ul><p>返回一个字符串，符合 JSON 字符串数组的格式，数组中的第 <em>i</em> 项为参数 <code>digests</code> 中的第 <em>i</em> 个元素所对应的语句。如果参数 <code>digests</code> 中的某一项不是一个有效的 SQL Digest 或系统无法查询到其对应的 SQL 语句，则返回结果中对应项为 <code>null</code>。如果指定了截断长度（<code>stmtTruncateLength &gt; 0</code>），则返回结果中每条超过该长度的语句，保留前 <code>stmtTruncateLength</code> 个字符，并在尾部增加 <code>"..."</code> 后缀表示发生了截断。如果参数 <code>digests</code> 为 <code>NULL</code>，则函数的返回值为 <code>NULL</code>。</p><style data-emotion="css 1weqspv">.css-1weqspv{padding-top:0.5rem;padding-bottom:0.5rem;}.css-1weqspv .MuiAlert-message p{margin-bottom:0px;margin-top:0px;}</style><div class="MuiBox-root css-1weqspv"><style data-emotion="css 17zlexa">.css-17zlexa{font-size:0.875rem;line-height:1.25rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:rgb(1, 67, 97);background-color:rgb(229, 246, 253);display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;padding:6px 16px;}.css-17zlexa .MuiAlert-icon{color:#03a9f4;}</style><style data-emotion="css 152gid5">.css-152gid5{background-color:#fff;color:rgba(0, 0, 0, 0.87);-webkit-transition:box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;border-radius:4px;box-shadow:none;font-size:0.875rem;line-height:1.25rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:rgb(1, 67, 97);background-color:rgb(229, 246, 253);display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;padding:6px 16px;}.css-152gid5 .MuiAlert-icon{color:#03a9f4;}</style><div class="MuiPaper-root MuiPaper-elevation MuiPaper-rounded MuiPaper-elevation0 MuiAlert-root MuiAlert-standardInfo MuiAlert-standard css-152gid5" role="alert"><style data-emotion="css 1l54tgj">.css-1l54tgj{margin-right:12px;padding:7px 0;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;font-size:22px;opacity:0.9;}</style><div class="MuiAlert-icon css-1l54tgj"><style data-emotion="css 1cw4hi4">.css-1cw4hi4{-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:1em;height:1em;display:inline-block;fill:currentColor;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;-webkit-transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;transition:fill 200ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;font-size:inherit;}</style><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="InfoOutlinedIcon"><path d="M11,9H13V7H11M12,20C7.59,20 4,16.41 4,12C4,7.59 7.59,4 12,4C16.41,4 20,7.59 20, 12C20,16.41 16.41,20 12,20M12,2A10,10 0 0,0 2,12A10,10 0 0,0 12,22A10,10 0 0,0 22,12A10, 10 0 0,0 12,2M11,17H13V11H11V17Z"/></svg></div><style data-emotion="css 1xsto0d">.css-1xsto0d{padding:8px 0;min-width:0;overflow:auto;}</style><div class="MuiAlert-message css-1xsto0d"><style data-emotion="css 1h2y6o4">.css-1h2y6o4{font-weight:500;margin-top:-2px;}</style><style data-emotion="css 17ioyuk">.css-17ioyuk{margin:0;font-size:1rem;line-height:1.5rem;font-family:"Helvetica Neue","sans-serif";font-weight:400;font-style:normal;color:#666666;margin-bottom:0.35em;font-weight:500;margin-top:-2px;}</style><div class="MuiTypography-root MuiTypography-body1 MuiTypography-gutterBottom MuiAlertTitle-root css-17ioyuk">注意</div><ul><li>仅持有 <a href="https://dev.mysql.com/doc/refman/8.0/en/privileges-provided.html#priv_process" target="_blank" referrerpolicy="no-referrer-when-downgrade">PROCESS</a> 权限的用户可以使用该函数。</li><li><code>TIDB_DECODE_SQL_DIGESTS</code> 执行时，TiDB 内部从 Statement Summary 一系列表中查询每个 SQL Digest 所对应的语句，因而并不能保证对任意 SQL Digest 都总是能查询到对应的语句，只有在集群中执行过的语句才有可能被查询到，且是否能查询到受 Statement Summary 表相关配置的影响。有关 Statement Summary 表的详细说明，参见 <a href="/zh/tidb/stable/statement-summary-tables">Statement Summary Tables</a>。</li><li>该函数开销较大，在行数很多的查询中（比如在规模较大、比较繁忙的集群上查询 <code>information_schema.cluster_tidb_trx</code> 全表时）直接使用该函数可能导致查询运行时间较长。请谨慎使用。<ul><li>该函数开销大的原因是，其每次被调用时，都会在内部发起对 <code>STATEMENTS_SUMMARY</code>、<code>STATEMENTS_SUMMARY_HISTORY</code>、<code>CLUSTER_STATEMENTS_SUMMARY</code> 和 <code>CLUSTER_STATEMENTS_SUMMARY_HISTORY</code> 这几张表的查询，且其中涉及 <code>UNION</code> 操作。且该函数目前不支持向量化，即对于多行数据调用该函数时，对每行都会独立进行一次上述的查询。</li></ul></li></ul></div></div></div><pre><code class="language-sql">set @digests = '["e6f07d43b5c21db0fbb9a31feac2dc599787763393dd5acbfad80e247eb02ad5","38b03afa5debbdf0326a014dbe5012a62c51957f1982b3093e748460f8b00821","e5796985ccafe2f71126ed6c0ac939ffa015a8c0744a24b7aee6d587103fd2f7"]'; select tidb_decode_sql_digests(@digests); </code></pre><pre><code class="language-sql">+------------------------------------+ | tidb_decode_sql_digests(@digests) | +------------------------------------+ | ["begin",null,"select * from `t`"] | +------------------------------------+ 1 row in set (0.00 sec) </code></pre><p>上面的例子中，参数是一个包含 3 个 SQL Digest 的 JSON 数组，其对应的 SQL 语句分别为查询结果中给出的三项。但是其中第二条 SQL Digest 所对应的 SQL 语句未能从集群中找到，因而结果中的第二项为 <code>null</code>。</p><pre><code class="language-sql">select tidb_decode_sql_digests(@digests, 10); </code></pre><pre><code class="language-sql">+---------------------------------------+ | tidb_decode_sql_digests(@digests, 10) | +---------------------------------------+ | ["begin",null,"select * f..."] | +---------------------------------------+ 1 row in set (0.01 sec) </code></pre><p>上述调用指定了第二个参数（即截断长度）为 10，而查询结果中的第三条语句的长度大于 10，因而仅保留了前 10 个字符，并在尾部添加了 <code>"..."</code> 表示发生了截断。</p><p>另请参阅：</p><ul><li><a href="/zh/tidb/stable/statement-summary-tables"><code>Statement Summary Tables</code></a></li><li><a href="/zh/tidb/stable/information-schema-tidb-trx"><code>INFORMATION_SCHEMA.TIDB_TRX</code></a></li></ul><h3 id="tidb_shard" style="position:relative"><a href="#tidb_shard" aria-label="tidb_shard permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_SHARD</h3><p><code>TIDB_SHARD</code> 函数用于创建一个 SHARD INDEX 来打散热点索引。SHARD INDEX 是一种以 <code>TIDB_SHARD</code> 函数为前缀的表达式索引。</p><ul><li><p>创建方式：</p><p> 使用 <code>uk((tidb_shard(a)), a))</code> 为字段 <code>a</code> 创建一个 SHARD INDEX。当二级唯一索引 <code>uk((tidb_shard(a)), a))</code> 的索引字段 <code>a</code> 上存在因单调递增或递减而产生的热点时，索引的前缀 <code>tidb_shard(a)</code> 会打散热点，从而提升集群可扩展性。</p></li><li><p>适用场景：</p><ul><li>二级唯一索引上 key 值存在单调递增或递减导致的写入热点，且该索引包含的列是整型。</li><li>业务中 SQL 语句根据该二级索引的全部字段做等值查询，查询可以是单独的 <code>SELECT</code>，也可以是 <code>UPDATE</code>，<code>DELETE</code> 等产生的内部查询，等值查询包括 <code>a = 1</code> 或 <code>a IN (1, 2, ......)</code> 两种方式。</li></ul></li><li><p>使用限制：</p><ul><li>非等值查询无法使用索引。</li><li>查询条件中 <code>AND</code> 和 <code>OR</code> 混合且最外层是 <code>AND</code> 算子时无法使用 SHARD INDEX。</li><li><code>GROUP BY</code> 无法使用 SHARD INDEX。</li><li><code>ORDER BY</code> 无法使用 SHARD INDEX。</li><li><code>ON</code> 子句无法使用 SHARD INDEX。</li><li><code>WHERE</code> 子查询无法使用 SHARD INDEX。</li><li>SHARD INDEX 只能打散整型字段的唯一索引。</li><li>SHARD INDEX 联合索引可能失效。</li><li>SHARD INDEX 无法走 FastPlan 流程，影响优化器性能。</li><li>SHARD INDEX 无法使用执行计划缓存。</li></ul></li></ul><p><code>TIDB_SHARD</code> 函数的使用示例如下：</p><ul><li><p>使用 <code>TIDB_SHARD</code> 函数计算 SHARD 值</p><p> 以下示例说明如何使用 <code>TIDB_SHARD</code> 函数计算 <code>12373743746</code> 的 SHARD 值。</p><pre><code class="language-sql">SELECT TIDB_SHARD(12373743746); </code></pre></li><li><p>计算得出 SHARD 值为：</p><pre><code class="language-sql">+-------------------------+ | TIDB_SHARD(12373743746) | +-------------------------+ | 184 | +-------------------------+ 1 row in set (0.00 sec) </code></pre></li><li><p>使用 <code>TIDB_SHARD</code> 函数创建 SHARD INDEX</p><pre><code class="language-sql">CREATE TABLE test(id INT PRIMARY KEY CLUSTERED, a INT, b INT, UNIQUE KEY uk((tidb_shard(a)), a)); </code></pre></li></ul><h3 id="tidb_row_checksum" style="position:relative"><a href="#tidb_row_checksum" aria-label="tidb_row_checksum permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>TIDB_ROW_CHECKSUM</h3><p><code>TIDB_ROW_CHECKSUM</code> 函数用于查询行数据的 Checksum 值。该函数只能用于 FastPlan 流程的 <code>SELECT</code> 语句，即你可通过形如 <code>SELECT TIDB_ROW_CHECKSUM() FROM t WHERE id = ?</code> 或 <code>SELECT TIDB_ROW_CHECKSUM() FROM t WHERE id IN (?, ?, ...)</code> 的语句进行查询。</p><p>在 TiDB 中开启行数据 Checksum 功能 <a href="/zh/tidb/stable/system-variables#tidb_enable_row_level_checksum-从-v710-版本开始引入"><code>tidb_enable_row_level_checksum</code></a>：</p><pre><code class="language-sql">SET GLOBAL tidb_enable_row_level_checksum = ON; </code></pre><p>创建表 <code>t</code> 并插入数据：</p><pre><code class="language-sql">USE test; CREATE TABLE t (id INT PRIMARY KEY, k INT, c int); INSERT INTO TABLE t values (1, 10, a); </code></pre><p>查询表 <code>t</code> 中 <code>id = 1</code> 的行数据的 Checksum 值：</p><pre><code class="language-sql">SELECT *, TIDB_ROW_CHECKSUM() FROM t WHERE id = 1; </code></pre><p>输出结果如下：</p><pre><code class="language-sql">+----+------+------+---------------------+ | id | k | c | TIDB_ROW_CHECKSUM() | +----+------+------+---------------------+ | 1 | 10 | a | 3813955661 | +----+------+------+---------------------+ 1 row in set (0.000 sec) </code></pre><h3 id="current_resource_group" style="position:relative"><a href="#current_resource_group" aria-label="current_resource_group permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>CURRENT_RESOURCE_GROUP</h3><p><code>CURRENT_RESOURCE_GROUP</code> 函数用于查询当前连接绑定的资源组名称。当开启<a href="/zh/tidb/stable/tidb-resource-control">资源管控 (Resource Control)</a> 功能时，执行 SQL 语句对资源的占用会受到所绑定的资源组资源配置的限制。</p><p>在会话建立时，TiDB 默认会将连接绑定至登录用户绑定的资源组，如果用户没有绑定任何资源组，则会将连接绑定至 <code>default</code> 资源组。在会话建立之后，绑定的资源组默认不会发生变化，即使执行了<a href="/zh/tidb/stable/sql-statement-alter-user#修改用户绑定的资源组">修改用户绑定的资源组</a>。如需修改当前会话绑定的资源组，可以使用 <a href="/zh/tidb/stable/sql-statement-set-resource-group"><code>SET RESOURCE GROUP</code></a> 语句。</p><h4 id="示例-1" style="position:relative"><a href="#%E7%A4%BA%E4%BE%8B-1" aria-label="示例 1 permalink" class="anchor before"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a>示例</h4><p>创建一个用户 <code>user1</code>，创建两个资源组 <code>rg1</code> 和 <code>rg2</code>，并将用户 <code>user1</code> 绑定资源组 <code>rg1</code>：</p><pre><code class="language-sql">CREATE USER 'user1'; CREATE RESOURCE GROUP 'rg1' RU_PER_SEC = 1000; CREATE RESOURCE GROUP 'rg2' RU_PER_SEC = 2000; ALTER USER 'user1' RESOURCE GROUP `rg1`; </code></pre><p>使用 <code>user1</code> 登录，查看当前用户绑定的资源组：</p><pre><code class="language-sql">SELECT CURRENT_RESOURCE_GROUP(); </code></pre><pre><code class="language-sql">+--------------------------+ | CURRENT_RESOURCE_GROUP() | +--------------------------+ | rg1 | +--------------------------+ 1 row in set (0.00 sec) </code></pre><p>执行 <code>SET RESOURCE GROUP</code> 将当前会话的资源组设置为 <code>rg2</code>，然后查看当前用户绑定的资源组：</p><pre><code class="language-sql">SET RESOURCE GROUP `rg2`; SELECT CURRENT_RESOURCE_GROUP(); </code></pre><pre><code class="language-sql">+--------------------------+