| import{_ as e,o as n,c as a,a as t,f as s}from"./app-ef44ea71.js";const o={},i=s(`<h1 id="aggregate-functions" tabindex="-1"><a class="header-anchor" href="#aggregate-functions" aria-hidden="true">#</a> Aggregate Functions</h1><p>Aggregate functions are many-to-one functions. They perform aggregate calculations on a set of values, resulting in a single aggregated result.</p><p>All aggregate functions except <code>COUNT()</code>, <code>COUNT_IF()</code> ignore null values and return null when there are no input rows or all values are null. For example, <code>SUM()</code> returns null instead of zero, and <code>AVG()</code> does not include null values in the count.</p><p>The aggregate functions supported by IoTDB are as follows:</p><table><thead><tr><th>Function Name</th><th>Function Description</th><th>Allowed Input Data Types</th><th>Output Data Types</th></tr></thead><tbody><tr><td>SUM</td><td>Summation.</td><td>INT32 INT64 FLOAT DOUBLE</td><td>DOUBLE</td></tr><tr><td>COUNT</td><td>Counts the number of data points.</td><td>All types</td><td>INT</td></tr><tr><td>AVG</td><td>Average.</td><td>INT32 INT64 FLOAT DOUBLE</td><td>DOUBLE</td></tr><tr><td>EXTREME</td><td>Finds the value with the largest absolute value. Returns a positive value if the maximum absolute value of positive and negative values is equal.</td><td>INT32 INT64 FLOAT DOUBLE</td><td>Consistent with the input data type</td></tr><tr><td>MAX_VALUE</td><td>Find the maximum value.</td><td>INT32 INT64 FLOAT DOUBLE</td><td>Consistent with the input data type</td></tr><tr><td>MIN_VALUE</td><td>Find the minimum value.</td><td>INT32 INT64 FLOAT DOUBLE</td><td>Consistent with the input data type</td></tr><tr><td>FIRST_VALUE</td><td>Find the value with the smallest timestamp.</td><td>All data types</td><td>Consistent with input data type</td></tr><tr><td>LAST_VALUE</td><td>Find the value with the largest timestamp.</td><td>All data types</td><td>Consistent with input data type</td></tr><tr><td>MAX_TIME</td><td>Find the maximum timestamp.</td><td>All data Types</td><td>Timestamp</td></tr><tr><td>MIN_TIME</td><td>Find the minimum timestamp.</td><td>All data Types</td><td>Timestamp</td></tr><tr><td>COUNT_IF</td><td>Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold.</td><td>BOOLEAN</td><td><code>[keep >=/>/=/!=/</<=]threshold</code>：The specified threshold or threshold condition, it is equivalent to <code>keep >= threshold</code> if <code>threshold</code> is used alone, type of <code>threshold</code> is <code>INT64</code><br> <code>ignoreNull</code>：Optional, default value is <code>true</code>；If the value is <code>true</code>, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is <code>true</code>, null values are not ignored, it means that if there are null values in the middle, continuity will be broken</td></tr></tbody></table><h2 id="count" tabindex="-1"><a class="header-anchor" href="#count" aria-hidden="true">#</a> COUNT</h2><h3 id="example" tabindex="-1"><a class="header-anchor" href="#example" aria-hidden="true">#</a> example</h3><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> <span class="token function">count</span><span class="token punctuation">(</span><span class="token keyword">status</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Result:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-------------------------------+ |
| |count(root.ln.wf01.wt01.status)| |
| +-------------------------------+ |
| | 10080| |
| +-------------------------------+ |
| Total line number = 1 |
| It costs 0.016s |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h2 id="count-if" tabindex="-1"><a class="header-anchor" href="#count-if" aria-hidden="true">#</a> COUNT_IF</h2><h3 id="grammar" tabindex="-1"><a class="header-anchor" href="#grammar" aria-hidden="true">#</a> Grammar</h3><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code>count_if<span class="token punctuation">(</span>predicate<span class="token punctuation">,</span> <span class="token punctuation">[</span>keep <span class="token operator">>=</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator">/</span><span class="token operator">=</span><span class="token operator">/</span><span class="token operator">!=</span><span class="token operator">/</span><span class="token operator"><</span><span class="token operator">/</span><span class="token operator"><=</span><span class="token punctuation">]</span>threshold<span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token string">'ignoreNull'</span><span class="token operator">=</span><span class="token string">'true/false'</span><span class="token punctuation">]</span><span class="token punctuation">)</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>predicate: legal expression with <code>BOOLEAN</code> return type</p><p>use of threshold and ignoreNull can see above table</p><blockquote><p>Note: count_if is not supported to use with SlidingWindow in group by time now</p></blockquote><h3 id="example-1" tabindex="-1"><a class="header-anchor" href="#example-1" aria-hidden="true">#</a> example</h3><h4 id="raw-data" tabindex="-1"><a class="header-anchor" href="#raw-data" aria-hidden="true">#</a> raw data</h4><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+-------------+-------------+ |
| | Time|root.db.d1.s1|root.db.d1.s2| |
| +-----------------------------+-------------+-------------+ |
| |1970-01-01T08:00:00.001+08:00| 0| 0| |
| |1970-01-01T08:00:00.002+08:00| null| 0| |
| |1970-01-01T08:00:00.003+08:00| 0| 0| |
| |1970-01-01T08:00:00.004+08:00| 0| 0| |
| |1970-01-01T08:00:00.005+08:00| 1| 0| |
| |1970-01-01T08:00:00.006+08:00| 1| 0| |
| |1970-01-01T08:00:00.007+08:00| 1| 0| |
| |1970-01-01T08:00:00.008+08:00| 0| 0| |
| |1970-01-01T08:00:00.009+08:00| 0| 0| |
| |1970-01-01T08:00:00.010+08:00| 0| 0| |
| +-----------------------------+-------------+-------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="not-use-ignorenull-attribute-ignore-null" tabindex="-1"><a class="header-anchor" href="#not-use-ignorenull-attribute-ignore-null" aria-hidden="true">#</a> Not use <code>ignoreNull</code> attribute (Ignore Null)</h4><p>SQL:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> count_if<span class="token punctuation">(</span>s1<span class="token operator">=</span><span class="token number">0</span> <span class="token operator">&</span> s2<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">,</span> count_if<span class="token punctuation">(</span>s1<span class="token operator">=</span><span class="token number">1</span> <span class="token operator">&</span> s2<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>db<span class="token punctuation">.</span>d1 |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Result:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+--------------------------------------------------+--------------------------------------------------+ |
| |count_if(root.db.d1.s1 = 0 & root.db.d1.s2 = 0, 3)|count_if(root.db.d1.s1 = 1 & root.db.d1.s2 = 0, 3)| |
| +--------------------------------------------------+--------------------------------------------------+ |
| | 2| 1| |
| +--------------------------------------------------+-------------------------------------------------- |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="use-ignorenull-attribute" tabindex="-1"><a class="header-anchor" href="#use-ignorenull-attribute" aria-hidden="true">#</a> Use <code>ignoreNull</code> attribute</h4><p>SQL:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> count_if<span class="token punctuation">(</span>s1<span class="token operator">=</span><span class="token number">0</span> <span class="token operator">&</span> s2<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token string">'ignoreNull'</span><span class="token operator">=</span><span class="token string">'false'</span><span class="token punctuation">)</span><span class="token punctuation">,</span> count_if<span class="token punctuation">(</span>s1<span class="token operator">=</span><span class="token number">1</span> <span class="token operator">&</span> s2<span class="token operator">=</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token string">'ignoreNull'</span><span class="token operator">=</span><span class="token string">'false'</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>db<span class="token punctuation">.</span>d1 |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>Result:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+------------------------------------------------------------------------+------------------------------------------------------------------------+ |
| |count_if(root.db.d1.s1 = 0 & root.db.d1.s2 = 0, 3, "ignoreNull"="false")|count_if(root.db.d1.s1 = 1 & root.db.d1.s2 = 0, 3, "ignoreNull"="false")| |
| +------------------------------------------------------------------------+------------------------------------------------------------------------+ |
| | 1| 1| |
| +------------------------------------------------------------------------+------------------------------------------------------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div>`,29);function d(l,r){return n(),a("div",null,[t(` |
| |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| |
| `),i])}const c=e(o,[["render",d],["__file","Aggregation.html.vue"]]);export{c as default}; |
