assets/Aggregation.html-d7e95b95.js

import{_ as t,O as e,P as d,ah as n,aW as r}from"./framework-62ad666a.js";const i={},o=r('<h1 id="聚合函数" tabindex="-1"><a class="header-anchor" href="#聚合函数" aria-hidden="true">#</a> 聚合函数</h1><p>聚合函数是多对一函数。它们对一组值进行聚合计算，得到单个聚合结果。</p><p>除了 <code>COUNT()</code> 之外，其他所有聚合函数都忽略空值，并在没有输入行或所有值为空时返回空值。 例如，<code>SUM()</code> 返回 null 而不是零，而 <code>AVG()</code> 在计数中不包括 null 值。</p><p>IoTDB 支持的聚合函数如下：</p><table><thead><tr><th>函数名</th><th>功能描述</th><th>允许的输入类型</th><th>输出类型</th></tr></thead><tbody><tr><td>SUM</td><td>求和。</td><td>INT32 INT64 FLOAT DOUBLE</td><td>DOUBLE</td></tr><tr><td>COUNT</td><td>计算数据点数。</td><td>所有类型</td><td>INT</td></tr><tr><td>AVG</td><td>求平均值。</td><td>INT32 INT64 FLOAT DOUBLE</td><td>DOUBLE</td></tr><tr><td>EXTREME</td><td>求具有最大绝对值的值。如果正值和负值的最大绝对值相等，则返回正值。</td><td>INT32 INT64 FLOAT DOUBLE</td><td>与输入类型一致</td></tr><tr><td>MAX_VALUE</td><td>求最大值。</td><td>INT32 INT64 FLOAT DOUBLE</td><td>与输入类型一致</td></tr><tr><td>MIN_VALUE</td><td>求最小值。</td><td>INT32 INT64 FLOAT DOUBLE</td><td>与输入类型一致</td></tr><tr><td>FIRST_VALUE</td><td>求时间戳最小的值。</td><td>所有类型</td><td>与输入类型一致</td></tr><tr><td>LAST_VALUE</td><td>求时间戳最大的值。</td><td>所有类型</td><td>与输入类型一致</td></tr><tr><td>MAX_TIME</td><td>求最大时间戳。</td><td>所有类型</td><td>Timestamp</td></tr><tr><td>MIN_TIME</td><td>求最小时间戳。</td><td>所有类型</td><td>Timestamp</td></tr></tbody></table>',5);function a(s,c){return e(),d("div",null,[n(`

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`),o])}const T=t(i,[["render",a],["__file","Aggregation.html.vue"]]);export{T as default};