相关文章推荐
小百科
›
日期和时间类型 | TiDB 文档中心
date
tidb
时间戳
date函数
大力的镜子
1 年前
</noscript><noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-TPX49SBK" height="0" width="0" style="display: none; visibility: hidden" aria-hidden="true"/></noscript><div id="___gatsby"><div style="outline:none" tabindex="-1" id="gatsby-focus-wrapper"><header class="MuiPaper-root MuiPaper-elevation MuiPaper-elevation4 MuiAppBar-root MuiAppBar-colorPrimary MuiAppBar-positionFixed doc-site-header mui-fixed css-1xx3vsu"><div class="MuiToolbar-root MuiToolbar-gutters MuiToolbar-regular css-j6gnra"><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeMedium css-iuftj9" tabindex="0" type="button" aria-label="menu"><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><div class="MuiBox-root css-13tqxrv"><a style="text-decoration:none" href="/zh/"><svg width="152" height="36" viewbox="0 0 152 36" fill="none"><g clip-path="url(#clip0_789_1365)"><path d="M0 26.9605V9.04959C0 9.01208 0.0187549 8.98395 0.0468872 8.96519L15.5478 0.00973267C15.5759 -0.00902222 15.6134 -0.00902222 15.6416 0.00973267L31.1425 8.95581C31.1706 8.97457 31.1894 9.0027 31.1894 9.04021V26.9511C31.1894 26.9886 31.1706 27.0168 31.1425 27.0355L15.6416 35.991C15.6134 36.0097 15.5759 36.0097 15.5478 35.991L0.0468872 27.0355C0.0187549 27.0168 0 26.9886 0 26.9605Z" fill="#DC150B"/><path d="M10.3808 15.0336C10.3714 15.0242 10.3527 15.0149 10.3433 15.0242L5.25136 17.9688H5.2326C5.21384 17.9688 5.20447 17.9594 5.20447 17.9406V12.0047C5.20447 11.9953 5.21384 11.986 5.22322 11.9766L5.22322 11.9766L15.5572 6.01253C15.5665 6.00315 15.5759 6.00315 15.5853 6.01253L20.7241 8.9758L20.7335 8.98518C20.7429 8.99455 20.7335 9.01331 20.7241 9.02268L15.5759 11.9953C15.5665 12.0047 15.5572 12.0141 15.5572 12.0235V29.9625V29.9813C15.5478 29.9906 15.529 30 15.5197 29.9906L10.3902 27.0368C10.3902 27.0274 10.3808 27.018 10.3808 27.0086V15.0524V15.0336Z" fill="white"/><path d="M20.7992 26.9992C20.7804 26.9992 20.7616 26.9805 20.7616 26.9617V15.0336C20.7616 15.0149 20.771 15.0055 20.7804 14.9961L25.9286 12.0235L25.9286 12.0235C25.938 12.0141 25.938 12.0141 25.9474 12.0141C25.9661 12.0141 25.9849 12.0328 25.9849 12.0516V23.9797C25.9849 23.9985 25.9755 24.0078 25.9661 24.0172L20.8179 26.9899C20.8085 26.9992 20.8085 26.9992 20.7992 26.9992Z" fill="white"/></g><path d="M37.1894 12.4971H42.0242V26.9998H45.4248V12.4971H50.2596V9.37683H37.1894V12.4971Z" fill="black"/><path d="M53.6372 9C53.1197 9 52.6672 9.18709 52.2887 9.55826C51.9102 9.92943 51.7151 10.3941 51.7151 10.9373C51.7151 11.4503 51.9073 11.8999 52.2858 12.2802C52.6643 12.6574 53.1167 12.8505 53.6342 12.8505C54.1517 12.8505 54.5775 12.6574 54.9501 12.2802C55.3227 11.903 55.509 11.4503 55.509 10.9373C55.509 10.3941 55.3257 9.93245 54.9619 9.56128C54.5982 9.19011 54.1517 9.00302 53.6372 9.00302V9Z" fill="black"/><path d="M55.2895 14.3592H51.9864V27H55.2895V14.3592Z" fill="black"/><path d="M64.3322 9.37683H58.2613V26.9998H64.3322C66.9492 26.9998 69.028 26.2031 70.5124 24.6309C71.9939 23.0587 72.748 20.8921 72.748 18.1883C72.748 15.4845 71.9969 13.2967 70.5124 11.7336C69.028 10.1705 66.9492 9.37683 64.3322 9.37683ZM61.6619 12.4971H64.2109C65.9024 12.4971 67.1798 12.998 68.0137 13.9847C68.8506 14.9775 69.2734 16.3566 69.2734 18.0857C69.2734 19.8148 68.8476 21.2512 68.0108 22.3013C67.1769 23.3454 65.8994 23.8765 64.208 23.8765H61.659V12.494L61.6619 12.4971Z" fill="black"/><path d="M86.5964 19.1388C86.0346 18.4418 85.3663 17.9409 84.6152 17.6512V17.621C86.1883 16.8424 86.9838 15.566 86.9838 13.8278C86.9838 12.479 86.5461 11.3866 85.6856 10.5839C84.8251 9.78421 83.5566 9.37683 81.9154 9.37683H74.7948V26.9998H81.8681C83.6068 26.9998 84.9907 26.5652 85.9784 25.7082C86.972 24.8482 87.4747 23.6261 87.4747 22.075C87.4747 20.8468 87.179 19.8601 86.5994 19.1388H86.5964ZM78.1185 16.5256V12.1953H81.4718C82.1105 12.1953 82.628 12.3884 83.0095 12.7686C83.388 13.1489 83.5802 13.68 83.5802 14.3499C83.5802 15.0198 83.3909 15.5569 83.0184 15.9432C82.6458 16.3294 82.1105 16.5256 81.4216 16.5256H78.1156H78.1185ZM83.9972 21.8245C83.9972 22.5276 83.7872 23.101 83.3762 23.5295C82.9651 23.958 82.356 24.1753 81.5724 24.1753H78.1215V19.3471H81.5724C82.3235 19.3471 82.9237 19.5794 83.3525 20.0411C83.7813 20.5028 84.0001 21.1033 84.0001 21.8215L83.9972 21.8245Z" fill="black"/><path d="M97.3306 26.5V9.7H102.299C107.771 9.7 111.083 12.868 111.083 18.1C111.083 23.332 107.771 26.5 102.299 26.5H97.3306ZM102.299 24.364C106.331 24.364 108.659 22.06 108.659 18.1C108.659 14.14 106.331 11.836 102.299 11.836H99.7066V24.364H102.299ZM118.968 26.764C115.464 26.764 112.824 24.052 112.824 20.5C112.824 16.948 115.464 14.236 118.968 14.236C122.472 14.236 125.112 16.948 125.112 20.5C125.112 24.052 122.472 26.764 118.968 26.764ZM118.968 24.628C121.152 24.628 122.736 22.876 122.736 20.5C122.736 18.124 121.152 16.372 118.968 16.372C116.784 16.372 115.2 18.124 115.2 20.5C115.2 22.876 116.784 24.628 118.968 24.628ZM132.772 26.764C129.22 26.764 126.7 24.124 126.7 20.5C126.7 16.876 129.22 14.236 132.772 14.236C135.652 14.236 137.884 15.964 138.244 18.532H135.844C135.532 17.236 134.332 16.372 132.772 16.372C130.588 16.372 129.076 18.076 129.076 20.5C129.076 22.9 130.588 24.628 132.772 24.628C134.332 24.628 135.532 23.764 135.844 22.468H138.244C137.884 25.036 135.652 26.764 132.772 26.764ZM144.557 26.764C141.677 26.764 139.781 25.108 139.709 22.732H142.085C142.229 23.956 142.973 24.724 144.581 24.724C145.733 24.724 146.765 24.34 146.765 23.332C146.765 22.588 146.333 22.06 145.157 21.7L143.333 21.172C141.173 20.548 140.093 19.3 140.093 17.716C140.093 15.604 141.965 14.236 144.413 14.236C146.885 14.236 148.685 15.7 148.829 17.74H146.453C146.285 16.828 145.445 16.204 144.341 16.204C143.261 16.204 142.469 16.804 142.469 17.716C142.469 18.412 142.925 18.868 144.245 19.228L146.069 19.732C148.109 20.308 149.141 21.556 149.141 23.188C149.141 25.396 147.197 26.764 144.557 26.764Z" fill="black"/><defs><clippath id="clip0_789_1365"><rect width="31.1894" height="36" fill="white"/></clippath></defs></svg></a></div><div class="css-2iqpys"><div class="MuiBox-root css-irbys9"><a style="text-decoration:none" hreflang="zh" href="/zh/tidb/stable/"><div class="MuiTypography-root MuiTypography-body1 css-195ggqq">TiDB</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-ae3kd9" target="_blank" href="https://asktug.com/" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-195ggqq">社区</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-ae3kd9" target="_blank" href="https://cn.pingcap.com/contact/" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-195ggqq">联系我们</div></a></div><div class="MuiBox-root css-kiou0g"><a class="MuiTypography-root MuiTypography-body1 css-ae3kd9" target="_blank" href="https://cn.pingcap.com/product/#SelectProduct" style="text-decoration:none"><div class="MuiTypography-root MuiTypography-body1 css-195ggqq"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" 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><div class="MuiBox-root css-1vn3uc0"><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textInherit MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-colorInherit MuiButton-disableElevation css-tjg32r" tabindex="0" type="button" id="header-nav-items" aria-haspopup="true"><span class="MuiButton-startIcon MuiButton-iconSizeMedium css-1l6c7y9"><svg width="152" height="36" viewbox="0 0 152 36" fill="none"><g clip-path="url(#clip0_789_1365)"><path d="M0 26.9605V9.04959C0 9.01208 0.0187549 8.98395 0.0468872 8.96519L15.5478 0.00973267C15.5759 -0.00902222 15.6134 -0.00902222 15.6416 0.00973267L31.1425 8.95581C31.1706 8.97457 31.1894 9.0027 31.1894 9.04021V26.9511C31.1894 26.9886 31.1706 27.0168 31.1425 27.0355L15.6416 35.991C15.6134 36.0097 15.5759 36.0097 15.5478 35.991L0.0468872 27.0355C0.0187549 27.0168 0 26.9886 0 26.9605Z" fill="#DC150B"/><path d="M10.3808 15.0336C10.3714 15.0242 10.3527 15.0149 10.3433 15.0242L5.25136 17.9688H5.2326C5.21384 17.9688 5.20447 17.9594 5.20447 17.9406V12.0047C5.20447 11.9953 5.21384 11.986 5.22322 11.9766L5.22322 11.9766L15.5572 6.01253C15.5665 6.00315 15.5759 6.00315 15.5853 6.01253L20.7241 8.9758L20.7335 8.98518C20.7429 8.99455 20.7335 9.01331 20.7241 9.02268L15.5759 11.9953C15.5665 12.0047 15.5572 12.0141 15.5572 12.0235V29.9625V29.9813C15.5478 29.9906 15.529 30 15.5197 29.9906L10.3902 27.0368C10.3902 27.0274 10.3808 27.018 10.3808 27.0086V15.0524V15.0336Z" fill="white"/><path d="M20.7992 26.9992C20.7804 26.9992 20.7616 26.9805 20.7616 26.9617V15.0336C20.7616 15.0149 20.771 15.0055 20.7804 14.9961L25.9286 12.0235L25.9286 12.0235C25.938 12.0141 25.938 12.0141 25.9474 12.0141C25.9661 12.0141 25.9849 12.0328 25.9849 12.0516V23.9797C25.9849 23.9985 25.9755 24.0078 25.9661 24.0172L20.8179 26.9899C20.8085 26.9992 20.8085 26.9992 20.7992 26.9992Z" fill="white"/></g><path d="M37.1894 12.4971H42.0242V26.9998H45.4248V12.4971H50.2596V9.37683H37.1894V12.4971Z" fill="black"/><path d="M53.6372 9C53.1197 9 52.6672 9.18709 52.2887 9.55826C51.9102 9.92943 51.7151 10.3941 51.7151 10.9373C51.7151 11.4503 51.9073 11.8999 52.2858 12.2802C52.6643 12.6574 53.1167 12.8505 53.6342 12.8505C54.1517 12.8505 54.5775 12.6574 54.9501 12.2802C55.3227 11.903 55.509 11.4503 55.509 10.9373C55.509 10.3941 55.3257 9.93245 54.9619 9.56128C54.5982 9.19011 54.1517 9.00302 53.6372 9.00302V9Z" fill="black"/><path d="M55.2895 14.3592H51.9864V27H55.2895V14.3592Z" fill="black"/><path d="M64.3322 9.37683H58.2613V26.9998H64.3322C66.9492 26.9998 69.028 26.2031 70.5124 24.6309C71.9939 23.0587 72.748 20.8921 72.748 18.1883C72.748 15.4845 71.9969 13.2967 70.5124 11.7336C69.028 10.1705 66.9492 9.37683 64.3322 9.37683ZM61.6619 12.4971H64.2109C65.9024 12.4971 67.1798 12.998 68.0137 13.9847C68.8506 14.9775 69.2734 16.3566 69.2734 18.0857C69.2734 19.8148 68.8476 21.2512 68.0108 22.3013C67.1769 23.3454 65.8994 23.8765 64.208 23.8765H61.659V12.494L61.6619 12.4971Z" fill="black"/><path d="M86.5964 19.1388C86.0346 18.4418 85.3663 17.9409 84.6152 17.6512V17.621C86.1883 16.8424 86.9838 15.566 86.9838 13.8278C86.9838 12.479 86.5461 11.3866 85.6856 10.5839C84.8251 9.78421 83.5566 9.37683 81.9154 9.37683H74.7948V26.9998H81.8681C83.6068 26.9998 84.9907 26.5652 85.9784 25.7082C86.972 24.8482 87.4747 23.6261 87.4747 22.075C87.4747 20.8468 87.179 19.8601 86.5994 19.1388H86.5964ZM78.1185 16.5256V12.1953H81.4718C82.1105 12.1953 82.628 12.3884 83.0095 12.7686C83.388 13.1489 83.5802 13.68 83.5802 14.3499C83.5802 15.0198 83.3909 15.5569 83.0184 15.9432C82.6458 16.3294 82.1105 16.5256 81.4216 16.5256H78.1156H78.1185ZM83.9972 21.8245C83.9972 22.5276 83.7872 23.101 83.3762 23.5295C82.9651 23.958 82.356 24.1753 81.5724 24.1753H78.1215V19.3471H81.5724C82.3235 19.3471 82.9237 19.5794 83.3525 20.0411C83.7813 20.5028 84.0001 21.1033 84.0001 21.8215L83.9972 21.8245Z" fill="black"/><path d="M97.3306 26.5V9.7H102.299C107.771 9.7 111.083 12.868 111.083 18.1C111.083 23.332 107.771 26.5 102.299 26.5H97.3306ZM102.299 24.364C106.331 24.364 108.659 22.06 108.659 18.1C108.659 14.14 106.331 11.836 102.299 11.836H99.7066V24.364H102.299ZM118.968 26.764C115.464 26.764 112.824 24.052 112.824 20.5C112.824 16.948 115.464 14.236 118.968 14.236C122.472 14.236 125.112 16.948 125.112 20.5C125.112 24.052 122.472 26.764 118.968 26.764ZM118.968 24.628C121.152 24.628 122.736 22.876 122.736 20.5C122.736 18.124 121.152 16.372 118.968 16.372C116.784 16.372 115.2 18.124 115.2 20.5C115.2 22.876 116.784 24.628 118.968 24.628ZM132.772 26.764C129.22 26.764 126.7 24.124 126.7 20.5C126.7 16.876 129.22 14.236 132.772 14.236C135.652 14.236 137.884 15.964 138.244 18.532H135.844C135.532 17.236 134.332 16.372 132.772 16.372C130.588 16.372 129.076 18.076 129.076 20.5C129.076 22.9 130.588 24.628 132.772 24.628C134.332 24.628 135.532 23.764 135.844 22.468H138.244C137.884 25.036 135.652 26.764 132.772 26.764ZM144.557 26.764C141.677 26.764 139.781 25.108 139.709 22.732H142.085C142.229 23.956 142.973 24.724 144.581 24.724C145.733 24.724 146.765 24.34 146.765 23.332C146.765 22.588 146.333 22.06 145.157 21.7L143.333 21.172C141.173 20.548 140.093 19.3 140.093 17.716C140.093 15.604 141.965 14.236 144.413 14.236C146.885 14.236 148.685 15.7 148.829 17.74H146.453C146.285 16.828 145.445 16.204 144.341 16.204C143.261 16.204 142.469 16.804 142.469 17.716C142.469 18.412 142.925 18.868 144.245 19.228L146.069 19.732C148.109 20.308 149.141 21.556 149.141 23.188C149.141 25.396 147.197 26.764 144.557 26.764Z" fill="black"/><defs><clippath id="clip0_789_1365"><rect width="31.1894" height="36" fill="white"/></clippath></defs></svg></span><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-pt151d"><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><div class="css-1w2hxsf"><div class="MuiBox-root css-19itmc6"><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="TranslateIcon"><path d="m12.87 15.07-2.54-2.51.03-.03c1.74-1.94 2.98-4.17 3.71-6.53H17V4h-7V2H8v2H1v1.99h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04zM18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12zm-2.62 7 1.62-4.33L19.12 17h-3.24z"/></svg></button><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textInherit MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-colorInherit MuiButton-disableElevation css-1r5wmim" tabindex="0" type="button" id="header-lang-switch" aria-haspopup="true"><span class="MuiButton-startIcon MuiButton-iconSizeMedium css-1l6c7y9"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1msahp5" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="TranslateIcon"><path d="m12.87 15.07-2.54-2.51.03-.03c1.74-1.94 2.98-4.17 3.71-6.53H17V4h-7V2H8v2H1v1.99h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04zM18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12zm-2.62 7 1.62-4.33L19.12 17h-3.24z"/></svg></span><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-pt151d"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1msahp5" 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><div class="css-1iegyem"><div class="MuiBox-root css-0"><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><form class="MuiBox-root css-1dl8tgy" novalidate="" autocomplete="off"><div class="MuiFormControl-root MuiFormControl-fullWidth MuiTextField-root css-7omol5"><div class="MuiInputBase-root MuiOutlinedInput-root MuiInputBase-colorPrimary MuiInputBase-fullWidth MuiInputBase-formControl MuiInputBase-sizeSmall MuiInputBase-adornedStart css-784vi5"><div class="MuiInputAdornment-root MuiInputAdornment-positionStart MuiInputAdornment-outlined MuiInputAdornment-sizeSmall css-1a6giau"><span class="notranslate"></span><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeSmall css-1k33q06" 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><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-kx70l9"/><fieldset aria-hidden="true" class="MuiOutlinedInput-notchedOutline css-igs3ac"><legend class="css-hdw1oc"><span class="notranslate"></span></legend></fieldset></div></div></form></div></div></div></div><div class="MuiBox-root css-pk5svg"><a href="https://labs.pingcap.com/?utm_source=docs&amp;utm_medium=direct&amp;utm_campaign=labs_zh_lp_04" target="_blank" class="css-1oh5qm"><div class="css-vb6e92"><div class="MuiBox-root css-0">🚀</div><span class="MuiTypography-root MuiTypography-body2 css-1xpq684">探索全新的 TiDB Labs，直接在浏览器中学习分布式 SQL 数据库并构建 RAG 应用。</span></div></a></div></header><div class="PingCAP-Doc doc-feature-banner MuiBox-root css-88zx00"><div class="MuiBox-root css-hboir5"><aside class="MuiBox-root css-2tzg8"><div class="MuiBox-root css-xskeex"><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textPrimary MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-disableElevation css-1q0sqyi" tabindex="0" type="button" id="version-select-button" aria-haspopup="true"><div class="MuiTypography-root MuiTypography-body1 css-1alj0g7">v8.5</div><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-pt151d"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1rrdqpg" 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><ul role="tree" id="left-nav-treeview" aria-multiselectable="false" class="MuiTreeView-root css-12mehxg" tabindex="0" aria-label="left navigation"><a class="MuiTypography-root MuiTypography-body1 css-ae3kd9" target="_blank" href="https://docs.pingcap.com/zh" style="text-decoration:none;width:100%;color:inherit"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-0" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">文档中心</div></div></div></div></div></div></li></a><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-1" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">关于 TiDB</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-2" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">快速上手</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-3" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">应用开发</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-4" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">部署标准集群</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-5" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数据迁移</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-6" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数据同步</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-7" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">运维操作</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-8" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">监控与告警</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-9" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">故障诊断</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-10" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">性能调优</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-11" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">教程</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-12" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">TiDB 工具</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-0-13" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-11fv84e" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">参考指南</div></div></div></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-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-0" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">架构</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-1" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">存储引擎 TiKV</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-2" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">存储引擎 TiFlash</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-3" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">TiDB 分布式执行框架</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/system-variables/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-4" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">系统变量</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/system-variable-reference/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-5" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">系统变量索引</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/status-variables/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-6" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">服务器状态变量</div></div></div></div></div></div></li></a><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-7" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">配置文件参数</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-8" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">CLI</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-9" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">命令行参数</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-10" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">监控指标</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-11" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">权限</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-0-13-12" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-11fv84e" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">SQL</div></div></div></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-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-0" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">SQL 语言结构和语法</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-1" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">SQL 语句</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-0-13-12-2" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-11fv84e" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数据类型</div></div></div></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"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/data-type-overview/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-0" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数据类型概述</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/data-type-default-values/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-1" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数据类型默认值</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/data-type-numeric/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-2" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">数值类型</div></div></div></div></div></div></li></a><a aria-current="page" style="text-decoration:none;width:100%;color:inherit" class="" href="/zh/tidb/stable/data-type-date-and-time/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-selected="true" id="left-nav-treeview-0-0-13-12-2-3" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded Mui-selected" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">日期和时间类型</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/data-type-string/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-4" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">字符串类型</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/data-type-json/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-5" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">JSON 类型</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/vector-search-data-types/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-2-6" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-gwjyeh"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">向量数据类型</div></div></div></div></div></div></li></a></div></div></ul></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-3" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">函数与操作符</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/clustered-indexes/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-4" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">聚簇索引</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/vector-search-index/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-5" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">向量索引</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/constraints/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-6" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">约束</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/generated-columns/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-7" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">生成列</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/sql-mode/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-8" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">SQL 模式</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/table-attributes/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-9" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">表属性</div></div></div></div></div></div></li></a><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-10" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">事务</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/views/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-11" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">视图</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/partitioned-table/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-12" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">分区表</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/temporary-tables/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-13" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">临时表</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/cached-tables/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-14" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">缓存表</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/foreign-key/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-15" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">外键约束</div></div></div></div></div></div></li></a><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-16" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">字符集和排序规则</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/placement-rules-in-sql/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-17" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">Placement Rules in SQL</div></div></div></div></div></div></li></a><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-13-12-18" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">系统表</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/metadata-lock/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-19" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">元数据锁</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/accelerated-table-creation/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-20" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">TiDB 加速建表</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/schema-cache/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-12-21" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">Schema 缓存</div></div></div></div></div></div></li></a></div></div></ul></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/telemetry/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-13" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">遥测</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/error-codes/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-14" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">错误码</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/schedule-replicas-by-topology-labels/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-15" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">通过拓扑 label 进行副本调度</div></div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/external-storage-uri/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-13-16" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">外部存储服务的 URI 格式</div></div></div></div></div></div></li></a></div></div></ul></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-14" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">常见问题解答 (FAQ)</div></div></div></div></div></div></li><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-0-15" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-1guu2k2" 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 class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">版本发布历史</div></div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/stable/glossary/"><li class="MuiTreeItem-root css-1p2jk91" role="treeitem" id="left-nav-treeview-0-0-16" tabindex="-1" style="margin-top:4px;margin-bottom:4px"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><div class="MuiBox-root css-f81823"/><div class="css-szjynw"><div class="MuiBox-root css-1uoa4hf"><div class="MuiTypography-root MuiTypography-body1 css-1g11p7i">术语表</div></div></div></div></div></div></li></a></ul></div></aside><main class="MuiBox-root css-sb2sd0"><div class="MuiBox-root css-w0vdto"><div class="css-1q5cbag"><div class="MuiBox-root css-was4pq"><div class="MuiContainer-root MuiContainer-maxWidthLg MuiContainer-disableGutters doc-content css-5csqms"><div class="markdown-body MuiBox-root css-0"><h1 id="日期和时间类型" style="position:relative">日期和时间类型<a href="#%E6%97%A5%E6%9C%9F%E5%92%8C%E6%97%B6%E9%97%B4%E7%B1%BB%E5%9E%8B" aria-label="日期和时间类型 permalink" class="anchor after"><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></h1><p>TiDB 支持 MySQL 所有的日期和时间类型，包括 <a href="#date-%E7%B1%BB%E5%9E%8B"><code>DATE</code></a>、<a href="#time-%E7%B1%BB%E5%9E%8B"><code>TIME</code></a>、<a href="#datetime-%E7%B1%BB%E5%9E%8B"><code>DATETIME</code></a>、<a href="#timestamp-%E7%B1%BB%E5%9E%8B"><code>TIMESTAMP</code></a> 以及 <a href="#year-%E7%B1%BB%E5%9E%8B"><code>YEAR</code></a>。完整信息可以参考 <a href="https://dev.mysql.com/doc/refman/8.0/en/date-and-time-types.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">MySQL 中的时间和日期类型</a>。</p><p>每种类型都有有效值范围，值为 0 表示无效值。此外，<code>TIMESTAMP</code> 和 <code>DATETIME</code> 类型能自动生成新的时间值。</p><p>关于日期和时间值类型，需要注意：</p><ul><li><p>日期部分必须是“年-月-日”的格式（例如 <code>1998-09-04</code>），而不是“月-日-年”或“日-月-年”的格式。</p></li><li><p>如果日期的年份部分是 2 位数，TiDB 会根据<a href="#%E5%B9%B4%E4%BB%BD%E4%B8%BA%E4%B8%A4%E4%BD%8D%E6%95%B0">年份为两位数的具体规则</a>进行转换。</p></li><li><p>如果格式必须是数值类型，TiDB 会自动将日期或时间值转换为数值类型。例如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">SELECT</span> NOW(), NOW()<span class="hljs-operator">+</span><span class="hljs-number">0</span>, NOW(<span class="hljs-number">3</span>)<span class="hljs-operator">+</span><span class="hljs-number">0</span>; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">---------------------+----------------+--------------------+</span> <span class="hljs-operator">|</span> NOW() <span class="hljs-operator">|</span> NOW()<span class="hljs-operator">+</span><span class="hljs-number">0</span> <span class="hljs-operator">|</span> NOW(<span class="hljs-number">3</span>)<span class="hljs-operator">+</span><span class="hljs-number">0</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">---------------------+----------------+--------------------+</span> <span class="hljs-operator">|</span> <span class="hljs-number">2012</span><span class="hljs-number">-08</span><span class="hljs-number">-15</span> <span class="hljs-number">09</span>:<span class="hljs-number">28</span>:<span class="hljs-number">00</span> <span class="hljs-operator">|</span> <span class="hljs-number">20120815092800</span> <span class="hljs-operator">|</span> <span class="hljs-number">20120815092800.889</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">---------------------+----------------+--------------------+</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>TiDB 可以自动将无效值转换同一类型的零值。是否进行转换取决于 SQL 模式的设置。比如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">show</span> <span class="hljs-keyword">create</span> <span class="hljs-keyword">table</span> t1; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">-------+---------------------------------------------------------------------------------------------------------+</span> <span class="hljs-operator">|</span> <span class="hljs-keyword">Table</span> <span class="hljs-operator">|</span> <span class="hljs-keyword">Create</span> <span class="hljs-keyword">Table</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------+---------------------------------------------------------------------------------------------------------+</span> <span class="hljs-operator">|</span> t1 <span class="hljs-operator">|</span> <span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">TABLE</span> `t1` ( `a` <span class="hljs-type">time</span> <span class="hljs-keyword">DEFAULT</span> <span class="hljs-keyword">NULL</span> ) ENGINE<span class="hljs-operator">=</span>InnoDB <span class="hljs-keyword">DEFAULT</span> CHARSET<span class="hljs-operator">=</span>utf8mb4 <span class="hljs-keyword">COLLATE</span><span class="hljs-operator">=</span>utf8mb4_bin <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------+---------------------------------------------------------------------------------------------------------+</span> <span class="hljs-number">1</span> <span class="hljs-type">row</span> <span class="hljs-keyword">in</span> <span class="hljs-keyword">set</span> (<span class="hljs-number">0.00</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">select</span> @<span class="hljs-variable">@sql</span>_mode; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">-------------------------------------------------------------------------------------------------------------------------------------------+</span> <span class="hljs-operator">|</span> @<span class="hljs-variable">@sql</span>_mode <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------------------------------------------------------------------------------------------------------------------------------------------+</span> <span class="hljs-operator">|</span> ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------------------------------------------------------------------------------------------------------------------------------------------+</span> <span class="hljs-number">1</span> <span class="hljs-type">row</span> <span class="hljs-keyword">in</span> <span class="hljs-keyword">set</span> (<span class="hljs-number">0.00</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">insert</span> <span class="hljs-keyword">into</span> t1 <span class="hljs-keyword">values</span> (`<span class="hljs-number">2090</span><span class="hljs-number">-11</span><span class="hljs-number">-32</span>:<span class="hljs-number">22</span>:<span class="hljs-number">33</span>:<span class="hljs-number">44</span>`); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">ERROR <span class="hljs-number">1292</span> (<span class="hljs-number">22007</span>): Truncated incorrect <span class="hljs-type">time</span> <span class="hljs-keyword">value</span>: `<span class="hljs-number">2090</span><span class="hljs-number">-11</span><span class="hljs-number">-32</span>:<span class="hljs-number">22</span>:<span class="hljs-number">33</span>:<span class="hljs-number">44</span>` </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">set</span> @<span class="hljs-variable">@sql</span>_mode<span class="hljs-operator">=</span>``; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">Query OK, <span class="hljs-number">0</span> <span class="hljs-keyword">rows</span> affected (<span class="hljs-number">0.01</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">insert</span> <span class="hljs-keyword">into</span> t1 <span class="hljs-keyword">values</span> (`<span class="hljs-number">2090</span><span class="hljs-number">-11</span><span class="hljs-number">-32</span>:<span class="hljs-number">22</span>:<span class="hljs-number">33</span>:<span class="hljs-number">44</span>`); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">Query OK, <span class="hljs-number">1</span> <span class="hljs-type">row</span> affected, <span class="hljs-number">1</span> warning (<span class="hljs-number">0.01</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">select</span> <span class="hljs-operator">*</span> <span class="hljs-keyword">from</span> t1; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">----------+</span> <span class="hljs-operator">|</span> a <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">----------+</span> <span class="hljs-operator">|</span> <span class="hljs-number">00</span>:<span class="hljs-number">00</span>:<span class="hljs-number">00</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">----------+</span> <span class="hljs-number">1</span> <span class="hljs-type">row</span> <span class="hljs-keyword">in</span> <span class="hljs-keyword">set</span> (<span class="hljs-number">0.01</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>SQL 模式的不同设置，会改变 TiDB 对格式的要求。</p></li><li><p>如果 SQL 模式的 <code>NO_ZERO_DATE</code> 被禁用，TiDB 允许 <code>DATE</code> 和 <code>DATETIME</code> 列中的月份或日期为零。例如，<code>2009-00-00</code> 或 <code>2009-01-00</code>。如果使用函数计算这种日期类型，例如使用 <code>DATE_SUB()</code> 或 <code>DATE_ADD()</code> 函数，计算结果可能不正确。</p></li><li><p>默认情况下，TiDB 启用 <code>NO_ZERO_DATE</code> SQL 模式。该模式可以避免存储像 <code>0000-00-00</code> 这样的零值。</p></li></ul><p>不同类型的零值如下表所示：</p><table><thead><tr><th align="left">数据类型</th><th align="left">零值</th></tr></thead><tbody><tr><td align="left">DATE</td><td align="left"><code>0000-00-00</code></td></tr><tr><td align="left">TIME</td><td align="left"><code>00:00:00</code></td></tr><tr><td align="left">DATETIME</td><td align="left"><code>0000-00-00 00:00:00</code></td></tr><tr><td align="left">TIMESTAMP</td><td align="left"><code>0000-00-00 00:00:00</code></td></tr><tr><td align="left">YEAR</td><td align="left">0000</td></tr></tbody></table><p>如果 SQL 模式允许使用无效的 <code>DATE</code>、<code>DATETIME</code>、<code>TIMESTAMP</code> 值，无效值会自动转换为相应的零值（<code>0000-00-00</code> 或 <code>0000-00-00 00:00:00</code>）。</p><h2 id="类型定义" style="position:relative">类型定义<a href="#%E7%B1%BB%E5%9E%8B%E5%AE%9A%E4%B9%89" aria-label="类型定义 permalink" class="anchor after"><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></h2><h3 id="date-类型" style="position:relative"><code>DATE</code> 类型<a href="#date-%E7%B1%BB%E5%9E%8B" aria-label="date 类型 permalink" class="anchor after"><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></h3><p><code>DATE</code> 类型只包含日期部分，不包含时间部分。<code>DATE</code> 类型的格式为 <code>YYYY-MM-DD</code>，支持的范围是 <code>0000-01-01</code> 到 <code>9999-12-31</code>。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-type">DATE</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h3 id="time-类型" style="position:relative"><code>TIME</code> 类型<a href="#time-%E7%B1%BB%E5%9E%8B" aria-label="time 类型 permalink" class="anchor after"><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></h3><p><code>TIME</code> 类型的格式为 <code>HH:MM:SS[.fraction]</code>，支持的范围是 <code>-838:59:59.000000</code> 到 <code>838:59:59.000000</code>。<code>TIME</code> 不仅可用于指示一天内的时间，还可用于指两个事件之间的时间间隔。<code>fsp</code> 参数表示秒精度，取值范围为：0 ~ 6，默认值为 0。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-type">TIME</span>[(fsp)] </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><div class="MuiBox-root css-1weqspv"><div class="MuiPaper-root MuiPaper-elevation MuiPaper-rounded MuiPaper-elevation0 MuiAlert-root MuiAlert-standardInfo MuiAlert-standard css-1bzshic" role="alert"><div class="MuiAlert-icon css-1l54tgj"><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><div class="MuiAlert-message css-1xsto0d"><div class="MuiTypography-root MuiTypography-body1 MuiTypography-gutterBottom MuiAlertTitle-root css-m00e13">注意</div><p>注意 <code>TIME</code> 的缩写形式。例如，<code>11:12</code> 表示 <code>11:12:00</code> 而不是 <code>00:11:12</code>。但是，<code>1112</code> 表示 <code>00:11:12</code>。这些差异取决于 <code>:</code> 字符的存在与否。</p></div></div></div><h3 id="datetime-类型" style="position:relative"><code>DATETIME</code> 类型<a href="#datetime-%E7%B1%BB%E5%9E%8B" aria-label="datetime 类型 permalink" class="anchor after"><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></h3><p><code>DATETIME</code> 类型是日期和时间的组合，格式为 <code>YYYY-MM-DD HH:MM:SS[.fraction]</code>。支持的范围是 <code>0000-01-01 00:00:00.000000</code> 到 <code>9999-12-31 23:59:59.999999</code>。<code>fsp</code> 参数表示秒精度，取值范围为 0~6，默认值为 0。TiDB 支持字符串或数字转换为 <code>DATETIME</code> 类型。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">DATETIME[(fsp)] </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h3 id="timestamp-类型" style="position:relative"><code>TIMESTAMP</code> 类型<a href="#timestamp-%E7%B1%BB%E5%9E%8B" aria-label="timestamp 类型 permalink" class="anchor after"><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></h3><p><code>TIMESTAMP</code> 类型是日期和时间的组合，支持的范围是 UTC 时间从 <code>1970-01-01 00:00:01.000000</code> 到 <code>2038-01-19 03:14:07.999999</code>。<code>fsp</code> 参数表示秒精度，取值范围为 0~6，默认值为 0。在 <code>TIMESTAMP</code> 中，不允许零出现在月份部分或日期部分，唯一的例外是零值本身 <code>0000-00-00 00:00:00</code>。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-type">TIMESTAMP</span>[(fsp)] </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h4 id="时区处理" style="position:relative">时区处理<a href="#%E6%97%B6%E5%8C%BA%E5%A4%84%E7%90%86" aria-label="时区处理 permalink" class="anchor after"><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></h4><p>当存储 <code>TIMESTAMP</code> 时，TiDB 会将当前时区的 <code>TIMESTAMP</code> 值转换为 UTC 时区。当读取 <code>TIMESTAMP</code> 时，TiDB 将存储的 <code>TIMESTAMP</code> 值从 UTC 时区转换为当前时区（注意：<code>DATETIME</code> 不会这样处理）。每次连接的默认时区是服务器的本地时区，可以通过环境变量 <code>time_zone</code> 进行修改。</p><div class="MuiBox-root css-1weqspv"><div class="MuiPaper-root MuiPaper-elevation MuiPaper-rounded MuiPaper-elevation0 MuiAlert-root MuiAlert-standardError MuiAlert-standard css-kdwypz" role="alert"><div class="MuiAlert-icon css-1l54tgj"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ErrorOutlineIcon"><path d="M11 15h2v2h-2zm0-8h2v6h-2zm.99-5C6.47 2 2 6.48 2 12s4.47 10 9.99 10C17.52 22 22 17.52 22 12S17.52 2 11.99 2zM12 20c-4.42 0-8-3.58-8-8s3.58-8 8-8 8 3.58 8 8-3.58 8-8 8z"/></svg></div><div class="MuiAlert-message css-1xsto0d"><div class="MuiTypography-root MuiTypography-body1 MuiTypography-gutterBottom MuiAlertTitle-root css-m00e13">警告</div><p>和 MySQL 一样，<code>TIMESTAMP</code> 数据类型受 <a href="https://zh.wikipedia.org/wiki/2038%E5%B9%B4%E9%97%AE%E9%A2%98" target="_blank" referrerpolicy="no-referrer-when-downgrade">2038 年问题</a>的影响。如果存储的值大于 2038，建议使用 <code>DATETIME</code> 类型。</p></div></div></div><h3 id="year-类型" style="position:relative"><code>YEAR</code> 类型<a href="#year-%E7%B1%BB%E5%9E%8B" aria-label="year 类型 permalink" class="anchor after"><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></h3><p><code>YEAR</code> 类型的格式为 <code>YYYY</code>，支持的值范围是 <code>1901</code> 到 <code>2155</code>，也支持零值 <code>0000</code>。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">YEAR</span>[(<span class="hljs-number">4</span>)] </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p><code>YEAR</code> 类型遵循以下格式规则：</p><ul><li>如果是四位数的数值，支持的范围是 <code>1901</code> 至 <code>2155</code>。</li><li>如果是四位数的字符串，支持的范围是 <code>'1901'</code> 到 <code>'2155'</code>。</li><li>如果是 1~99 之间的一位数或两位数的数字，1~69 换算成 2001~2069，70~99 换算成 1970~1999。</li><li>支持 <code>'0'</code> 到 <code>'99'</code> 之间的一位数或两位数字符串的范围</li><li>将数值 <code>0</code> 转换为 <code>0000</code>，将字符串 <code>'0'</code> 或 <code>'00'</code> 转换为 <code>'2000'</code>。</li></ul><p>无效的 <code>YEAR</code> 值会自动转换为 <code>0000</code>（如果用户没有使用 <code>NO_ZERO_DATE</code> SQL 模式）。</p><h2 id="自动初始化和更新-timestamp-或-datetime" style="position:relative">自动初始化和更新 <code>TIMESTAMP</code> 或 <code>DATETIME</code><a href="#%E8%87%AA%E5%8A%A8%E5%88%9D%E5%A7%8B%E5%8C%96%E5%92%8C%E6%9B%B4%E6%96%B0-timestamp-%E6%88%96-datetime" aria-label="自动初始化和更新 timestamp 或 datetime permalink" class="anchor after"><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></h2><p>带有 <code>TIMESTAMP</code> 或 <code>DATETIME</code> 数据类型的列可以自动初始化为或更新为当前时间。</p><p>对于表中任何带有 <code>TIMESTAMP</code> 或 <code>DATETIME</code> 数据类型的列，你可以设置默认值，或自动更新为当前时间戳。</p><p>在定义列的时候，<code>TIMESTAMP</code> 和 <code>DATETIME</code> 可以通过 <code>DEFAULT CURRENT_TIMESTAMP</code> 和 <code>ON UPDATE CURRENT_TIMESTAMP</code> 来设置。<code>DEFAULT</code> 也可以设置为一个特定的值，例如 <code>DEFAULT 0</code> 或 <code>DEFAULT '2000-01-01 00:00:00'</code>。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">TABLE</span> t1 ( ts <span class="hljs-type">TIMESTAMP</span> <span class="hljs-keyword">DEFAULT</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span> <span class="hljs-keyword">ON</span> <span class="hljs-keyword">UPDATE</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span>, dt DATETIME <span class="hljs-keyword">DEFAULT</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span> <span class="hljs-keyword">ON</span> <span class="hljs-keyword">UPDATE</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>除非指定 <code>DATETIME</code> 的值为 <code>NOT NULL</code>，否则默认 <code>DATETIME</code> 的值为 <code>NULL</code>。指定 <code>DATETIME</code> 的值为 <code>NOT NULL</code> 时，如果没有设置默认值，则默认值为 <code>0</code>。</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">TABLE</span> t1 ( dt1 DATETIME <span class="hljs-keyword">ON</span> <span class="hljs-keyword">UPDATE</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span>, <span class="hljs-comment">-- default NULL</span> dt2 DATETIME <span class="hljs-keyword">NOT</span> <span class="hljs-keyword">NULL</span> <span class="hljs-keyword">ON</span> <span class="hljs-keyword">UPDATE</span> <span class="hljs-built_in">CURRENT_TIMESTAMP</span> <span class="hljs-comment">-- default 0</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h2 id="时间值的小数部分" style="position:relative">时间值的小数部分<a href="#%E6%97%B6%E9%97%B4%E5%80%BC%E7%9A%84%E5%B0%8F%E6%95%B0%E9%83%A8%E5%88%86" aria-label="时间值的小数部分 permalink" class="anchor after"><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></h2><p><code>DATETIME</code> 和 <code>TIMESTAMP</code> 值最多可以有 6 位小数，精确到微秒。如果包含小数部分，值的格式为 <code>YYYY-MM-DD HH:MM:SS[.fraction]</code>，小数部分的范围为 <code>000000</code> 到<code>999999</code>。必须使用小数点分隔小数部分与其他部分。</p><ul><li><p>使用 <code>type_name(fsp)</code> 可以定义精确到小数的列，其中 <code>type_name</code> 可以是<code>TIME</code>、<code>DATETIME</code> 或 <code>TIMESTAMP</code>。例如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">TABLE</span> t1 (t <span class="hljs-type">TIME</span>(<span class="hljs-number">3</span>), dt DATETIME(<span class="hljs-number">6</span>)); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> <code>fsp</code> 范围是 <code>0</code> 到 <code>6</code>。</p><p> <code>0</code> 表示没有小数部分。如果省略了 <code>fsp</code>，默认为 <code>0</code>。</p></li><li><p>当插入包含小数部分的 <code>TIME</code>、<code>DATETIME</code> 或 <code>TIMESTAMP</code> 时，如果小数部分的位数过少或过多，可能需要进行四舍五入。例如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">TABLE</span> fractest( c1 <span class="hljs-type">TIME</span>(<span class="hljs-number">2</span>), c2 DATETIME(<span class="hljs-number">2</span>), c3 <span class="hljs-type">TIMESTAMP</span>(<span class="hljs-number">2</span>) ); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">Query OK, <span class="hljs-number">0</span> <span class="hljs-keyword">rows</span> affected (<span class="hljs-number">0.33</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">INSERT</span> <span class="hljs-keyword">INTO</span> fractest <span class="hljs-keyword">VALUES</span> <span class="hljs-operator">&gt;</span> (<span class="hljs-string">'17:51:04.777'</span>, <span class="hljs-string">'2014-09-08 17:51:04.777'</span>, <span class="hljs-string">'2014-09-08 17:51:04.777'</span>); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">Query OK, <span class="hljs-number">1</span> <span class="hljs-type">row</span> affected (<span class="hljs-number">0.03</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">SELECT</span> <span class="hljs-operator">*</span> <span class="hljs-keyword">FROM</span> fractest; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">-------------|------------------------|------------------------+</span> <span class="hljs-operator">|</span> c1 <span class="hljs-operator">|</span> c2 <span class="hljs-operator">|</span> c3 <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------------|------------------------|------------------------+</span> <span class="hljs-operator">|</span> <span class="hljs-number">17</span>:<span class="hljs-number">51</span>:<span class="hljs-number">04.78</span> <span class="hljs-operator">|</span> <span class="hljs-number">2014</span><span class="hljs-number">-09</span><span class="hljs-number">-08</span> <span class="hljs-number">17</span>:<span class="hljs-number">51</span>:<span class="hljs-number">04.78</span> <span class="hljs-operator">|</span> <span class="hljs-number">2014</span><span class="hljs-number">-09</span><span class="hljs-number">-08</span> <span class="hljs-number">17</span>:<span class="hljs-number">51</span>:<span class="hljs-number">04.78</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-------------|------------------------|------------------------+</span> <span class="hljs-number">1</span> <span class="hljs-type">row</span> <span class="hljs-keyword">in</span> <span class="hljs-keyword">set</span> (<span class="hljs-number">0.00</span> sec) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li></ul><h2 id="日期和时间类型的转换" style="position:relative">日期和时间类型的转换<a href="#%E6%97%A5%E6%9C%9F%E5%92%8C%E6%97%B6%E9%97%B4%E7%B1%BB%E5%9E%8B%E7%9A%84%E8%BD%AC%E6%8D%A2" aria-label="日期和时间类型的转换 permalink" class="anchor after"><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></h2><p>在日期和时间类型之间进行转换时，有些转换可能会导致信息丢失。例如，<code>DATE</code>、<code>DATETIME</code> 和 <code>TIMESTAMP</code> 都有各自的有效值范围。<code>TIMESTAMP</code> 不能早于 UTC 时间的 1970 年，也不能晚于 UTC 时间的 <code>2038-01-19 03:14:07</code>。根据这个规则，<code>1968-01-01</code> 对于 <code>DATE</code> 或 <code>DATETIME</code> 是有效的，但当 <code>1968-01-01</code> 转换为 <code>TIMESTAMP</code> 时，就会变成 0。</p><p><code>DATE</code> 的转换：</p><ul><li>当 <code>DATE</code> 转换为 <code>DATETIME</code> 或 <code>TIMESTAMP</code> 时，会添加时间部分 <code>00:00:00</code>，因为 <code>DATE</code> 不包含任何时间信息。</li><li>当 <code>DATE</code> 转换为 <code>TIME</code> 时，结果是 <code>00:00:00</code>。</li></ul><p><code>DATETIME</code> 或 <code>TIMESTAMP</code> 的转换：</p><ul><li>当 <code>DATETIME</code> 或 <code>TIMESTAMP</code> 转换为 <code>DATE</code> 时，时间和小数部分将被舍弃。例如，<code>1999-12-31 23:59:59.499</code> 被转换为 <code>1999-12-31</code>。</li><li>当 <code>DATETIME</code> 或 <code>TIMESTAMP</code> 转换为 <code>TIME</code> 时，日期部分被舍弃，因为 <code>TIME</code> 不包含任何日期信息。</li></ul><p>如果要将 <code>TIME</code> 转换为其他时间和日期格式，日期部分会自动指定为 <code>CURRENT_DATE()</code>。最终的转换结果是由 <code>TIME</code> 和 <code>CURRENT_DATE()</code> 组成的日期。也就是说，如果 <code>TIME</code> 的值超出了 <code>00:00:00</code> 到 <code>23:59:59</code> 的范围，那么转换后的日期部分并不表示当前的日期。</p><p>当 <code>TIME</code> 转换为 <code>DATE</code> 时，转换过程类似，时间部分被舍弃。</p><p>使用 <code>CAST()</code> 函数可以显式地将值转换为 <code>DATE</code> 类型。例如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia">date_col <span class="hljs-operator">=</span> <span class="hljs-built_in">CAST</span>(datetime_col <span class="hljs-keyword">AS</span> <span class="hljs-type">DATE</span>) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>将 <code>TIME</code> 和 <code>DATETIME</code> 转换为数字格式。例如：</p><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">SELECT</span> CURTIME(), CURTIME()<span class="hljs-operator">+</span><span class="hljs-number">0</span>, CURTIME(<span class="hljs-number">3</span>)<span class="hljs-operator">+</span><span class="hljs-number">0</span>; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-operator">+</span><span class="hljs-comment">-----------|-------------|--------------+</span> <span class="hljs-operator">|</span> CURTIME() <span class="hljs-operator">|</span> CURTIME()<span class="hljs-operator">+</span><span class="hljs-number">0</span> <span class="hljs-operator">|</span> CURTIME(<span class="hljs-number">3</span>)<span class="hljs-operator">+</span><span class="hljs-number">0</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-----------|-------------|--------------+</span> <span class="hljs-operator">|</span> <span class="hljs-number">09</span>:<span class="hljs-number">28</span>:<span class="hljs-number">00</span> <span class="hljs-operator">|</span> <span class="hljs-number">92800</span> <span class="hljs-operator">|</span> <span class="hljs-number">92800.887</span> <span class="hljs-operator">|</span> <span class="hljs-operator">+</span><span class="hljs-comment">-----------|-------------|--------------+</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><pre><code class="hljs language-sql"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">SELECT</span> NOW(), NOW()<span class="hljs-operator">+</span><span class="hljs-number">0</span>, NOW(<span class="hljs-number">3</span>)<span class="hljs-operator">+</span><span class="hljs-number">0</span>;
推荐文章
