| import{_ as n,O as e,P as s,ah as a,aW as t}from"./framework-e4340ccd.js";const i={},l=t(`<h2 id="趋势计算函数" tabindex="-1"><a class="header-anchor" href="#趋势计算函数" aria-hidden="true">#</a> 趋势计算函数</h2><p>目前 IoTDB 支持如下趋势计算函数：</p><table><thead><tr><th>函数名</th><th>输入序列类型</th><th>输出序列类型</th><th>功能描述</th></tr></thead><tbody><tr><td>TIME_DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE / BOOLEAN / TEXT</td><td>INT64</td><td>统计序列中某数据点的时间戳与前一数据点时间戳的差。范围内第一个数据点没有对应的结果输出。</td></tr><tr><td>DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>与输入序列的实际类型一致</td><td>统计序列中某数据点的值与前一数据点的值的差。范围内第一个数据点没有对应的结果输出。</td></tr><tr><td>NON_NEGATIVE_DIFFERENCE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>与输入序列的实际类型一致</td><td>统计序列中某数据点的值与前一数据点的值的差的绝对值。范围内第一个数据点没有对应的结果输出。</td></tr><tr><td>DERIVATIVE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>DOUBLE</td><td>统计序列中某数据点相对于前一数据点的变化率，数量上等同于 DIFFERENCE / TIME_DIFFERENCE。范围内第一个数据点没有对应的结果输出。</td></tr><tr><td>NON_NEGATIVE_DERIVATIVE</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td>DOUBLE</td><td>统计序列中某数据点相对于前一数据点的变化率的绝对值，数量上等同于 NON_NEGATIVE_DIFFERENCE / TIME_DIFFERENCE。范围内第一个数据点没有对应的结果输出。</td></tr></tbody></table><p>例如：</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>结果：</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>函数名</th><th>输入序列类型</th><th>参数</th><th>输出序列类型</th><th>功能描述</th></tr></thead><tbody><tr><td>DIFF</td><td>INT32 / INT64 / FLOAT / DOUBLE</td><td><code>ignoreNull</code>：可选，默认为true；为true时，前一个数据点值为null时，忽略该数据点继续向前找到第一个出现的不为null的值；为false时，如果前一个数据点为null，则不忽略，使用null进行相减，结果也为null</td><td>DOUBLE</td><td>统计序列中某数据点的值与前一数据点的值的差。第一个数据点没有对应的结果输出，输出值为null</td></tr></tbody></table><h4 id="使用示例" tabindex="-1"><a class="header-anchor" href="#使用示例" aria-hidden="true">#</a> 使用示例</h4><h5 id="原始数据" tabindex="-1"><a class="header-anchor" href="#原始数据" aria-hidden="true">#</a> 原始数据</h5><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><h5 id="不使用ignorenull参数-忽略null" tabindex="-1"><a class="header-anchor" href="#不使用ignorenull参数-忽略null" aria-hidden="true">#</a> 不使用ignoreNull参数(忽略null)</h5><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>输出:</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><h5 id="使用ignorenull参数" tabindex="-1"><a class="header-anchor" href="#使用ignorenull参数" aria-hidden="true">#</a> 使用ignoreNull参数</h5><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>输出:</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 d(o,r){return e(),s("div",null,[a(` |
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| `),l])}const c=n(i,[["render",d],["__file","Variation-Trend.html.vue"]]);export{c as default}; |
