| import{_ as e,O as n,P as t,ah as a,aW as s}from"./framework-e4340ccd.js";const i={},l=s(`<h1 id="variation-trend-calculation-functions" tabindex="-1"><a class="header-anchor" href="#variation-trend-calculation-functions" aria-hidden="true">#</a> Variation Trend Calculation Functions</h1><p>Currently, IoTDB supports the following variation trend calculation functions:</p><table><thead><tr><th>Function Name</th><th>Allowed Input Series Data Types</th><th>Output Series Data Type</th><th>Description</th></tr></thead><tbody><tr><td>TIME_DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE / BOOLEAN / TEXT</td><td>INT64</td><td>Calculates the difference between the time stamp of a data point and the time stamp of the previous data point. There is no corresponding output for the first data point.</td></tr><tr><td>DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>Same type as the input series</td><td>Calculates the difference between the value of a data point and the value of the previous data point. There is no corresponding output for the first data point.</td></tr><tr><td>NON_NEGATIVE_DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>Same type as the input series</td><td>Calculates the absolute value of the difference between the value of a data point and the value of the previous data point. There is no corresponding output for the first data point.</td></tr><tr><td>DERIVATIVE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>DOUBLE</td><td>Calculates the rate of change of a data point compared to the previous data point, the result is equals to DIFFERENCE / TIME_DIFFERENCE. There is no corresponding output for the first data point.</td></tr><tr><td>NON_NEGATIVE_DERIVATIVE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>DOUBLE</td><td>Calculates the absolute value of the rate of change of a data point compared to the previous data point, the result is equals to NON_NEGATIVE_DIFFERENCE / TIME_DIFFERENCE. There is no corresponding output for the first data point.</td></tr></tbody></table><p>Example:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> s1<span class="token punctuation">,</span> time_difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> non_negative_difference<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> derivative<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> non_negative_derivative<span class="token punctuation">(</span>s1<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1 <span class="token keyword">limit</span> <span class="token number">5</span> <span class="token keyword">offset</span> <span class="token number">1000</span><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>+-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+ |
| | Time| root.sg1.d1.s1|time_difference(root.sg1.d1.s1)|difference(root.sg1.d1.s1)|non_negative_difference(root.sg1.d1.s1)|derivative(root.sg1.d1.s1)|non_negative_derivative(root.sg1.d1.s1)| |
| +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+ |
| |2020-12-10T17:11:49.037+08:00|7360723084922759782| 1| -8431715764844238876| 8431715764844238876| -8.4317157648442388E18| 8.4317157648442388E18| |
| |2020-12-10T17:11:49.038+08:00|4377791063319964531| 1| -2982932021602795251| 2982932021602795251| -2.982932021602795E18| 2.982932021602795E18| |
| |2020-12-10T17:11:49.039+08:00|7972485567734642915| 1| 3594694504414678384| 3594694504414678384| 3.5946945044146785E18| 3.5946945044146785E18| |
| |2020-12-10T17:11:49.040+08:00|2508858212791964081| 1| -5463627354942678834| 5463627354942678834| -5.463627354942679E18| 5.463627354942679E18| |
| |2020-12-10T17:11:49.041+08:00|2817297431185141819| 1| 308439218393177738| 308439218393177738| 3.0843921839317773E17| 3.0843921839317773E17| |
| +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+ |
| Total line number = 5 |
| It costs 0.014s |
| </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></div><table><thead><tr><th>Function Name</th><th>Allowed Input Series Data Types</th><th>Attributes</th><th>Output Series Data Type</th><th>Description</th></tr></thead><tbody><tr><td>DIFF</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td><code>ignoreNull</code>：optional，default is true. If is true, the previous data point is ignored when it is null and continues to find the first non-null value forwardly. If the value is false, previous data point is not ignored when it is null, the result is also null because null is used for subtraction</td><td>DOUBLE</td><td>Calculates the difference between the value of a data point and the value of the previous data point. There is no corresponding output for the first data point, so output is null</td></tr></tbody></table><h3 id="example" tabindex="-1"><a class="header-anchor" href="#example" aria-hidden="true">#</a> Example</h3><h4 id="rawdata" tabindex="-1"><a class="header-anchor" href="#rawdata" aria-hidden="true">#</a> RawData</h4><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+------------+------------+ |
| | Time|root.test.s1|root.test.s2| |
| +-----------------------------+------------+------------+ |
| |1970-01-01T08:00:00.001+08:00| 1| 1.0| |
| |1970-01-01T08:00:00.002+08:00| 2| null| |
| |1970-01-01T08:00:00.003+08:00| null| 3.0| |
| |1970-01-01T08:00:00.004+08:00| 4| null| |
| |1970-01-01T08:00:00.005+08:00| 5| 5.0| |
| |1970-01-01T08:00:00.006+08:00| null| 6.0| |
| +-----------------------------+------------+------------+ |
| </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></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> DIFF<span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span> DIFF<span class="token punctuation">(</span>s2<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>test<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>+-----------------------------+------------------+------------------+ |
| | Time|DIFF(root.test.s1)|DIFF(root.test.s2)| |
| +-----------------------------+------------------+------------------+ |
| |1970-01-01T08:00:00.001+08:00| null| null| |
| |1970-01-01T08:00:00.002+08:00| 1.0| null| |
| |1970-01-01T08:00:00.003+08:00| null| 2.0| |
| |1970-01-01T08:00:00.004+08:00| 2.0| null| |
| |1970-01-01T08:00:00.005+08:00| 1.0| 2.0| |
| |1970-01-01T08:00:00.006+08:00| null| 1.0| |
| +-----------------------------+------------------+------------------+ |
| </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></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> DIFF<span class="token punctuation">(</span>s1<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> DIFF<span class="token punctuation">(</span>s2<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>test<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>+-----------------------------+----------------------------------------+----------------------------------------+ |
| | Time|DIFF(root.test.s1, "ignoreNull"="false")|DIFF(root.test.s2, "ignoreNull"="false")| |
| +-----------------------------+----------------------------------------+----------------------------------------+ |
| |1970-01-01T08:00:00.001+08:00| null| null| |
| |1970-01-01T08:00:00.002+08:00| 1.0| null| |
| |1970-01-01T08:00:00.003+08:00| null| null| |
| |1970-01-01T08:00:00.004+08:00| null| null| |
| |1970-01-01T08:00:00.005+08:00| 1.0| null| |
| |1970-01-01T08:00:00.006+08:00| null| 1.0| |
| +-----------------------------+----------------------------------------+----------------------------------------+ |
| </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></div>`,21);function o(d,r){return n(),t("div",null,[a(` |
| |
| 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. |
| |
| `),l])}const c=e(i,[["render",o],["__file","Variation-Trend.html.vue"]]);export{c as default}; |
