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import{_ as a,C as t,O as i,P as o,ah as r,Q as n,U as s,ai as l,aW as p}from"./framework-e4340ccd.js";const c={},d=n("h1",{id:"lambda-expression",tabindex:"-1"},[n("a",{class:"header-anchor",href:"#lambda-expression","aria-hidden":"true"},"#"),s(" Lambda Expression")],-1),u=n("h2",{id:"jexl-function",tabindex:"-1"},[n("a",{class:"header-anchor",href:"#jexl-function","aria-hidden":"true"},"#"),s(" JEXL Function")],-1),m={href:"https://commons.apache.org/proper/commons-jexl/apidocs/org/apache/commons/jexl3/package-summary.html#customization",target:"_blank",rel:"noopener noreferrer"},v=p(`<table><thead><tr><th>Function Name</th><th>Allowed Input Series Data Types</th><th>Required Attributes</th><th>Output Series Data Type</th><th>Series Data Type Description</th></tr></thead><tbody><tr><td>JEXL</td><td>INT32 / INT64 / FLOAT / DOUBLE / TEXT / BOOLEAN</td><td><code>expr</code> is a lambda expression that supports standard one or multi arguments in the form <code>x -&gt; {...}</code> or <code>(x, y, z) -&gt; {...}</code>, e.g. <code> x -&gt; {x * 2}</code>, <code>(x, y, z) -&gt; {x + y * z}</code></td><td>INT32 / INT64 / FLOAT / DOUBLE / TEXT / BOOLEAN</td><td>Returns the input time series transformed by a lambda expression</td></tr></tbody></table><h4 id="demonstrate" tabindex="-1"><a class="header-anchor" href="#demonstrate" aria-hidden="true">#</a> Demonstrate</h4><p>Example data: <code>root.ln.wf01.wt01.temperature</code>, <code>root.ln.wf01.wt01.st</code>, <code>root.ln.wf01.wt01.str</code> a total of <code>11</code> data.</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB&gt; select * from root.ln.wf01.wt01;
+-----------------------------+---------------------+--------------------+-----------------------------+
| Time|root.ln.wf01.wt01.str|root.ln.wf01.wt01.st|root.ln.wf01.wt01.temperature|
+-----------------------------+---------------------+--------------------+-----------------------------+
|1970-01-01T08:00:00.000+08:00| str| 10.0| 0.0|
|1970-01-01T08:00:00.001+08:00| str| 20.0| 1.0|
|1970-01-01T08:00:00.002+08:00| str| 30.0| 2.0|
|1970-01-01T08:00:00.003+08:00| str| 40.0| 3.0|
|1970-01-01T08:00:00.004+08:00| str| 50.0| 4.0|
|1970-01-01T08:00:00.005+08:00| str| 60.0| 5.0|
|1970-01-01T08:00:00.006+08:00| str| 70.0| 6.0|
|1970-01-01T08:00:00.007+08:00| str| 80.0| 7.0|
|1970-01-01T08:00:00.008+08:00| str| 90.0| 8.0|
|1970-01-01T08:00:00.009+08:00| str| 100.0| 9.0|
|1970-01-01T08:00:00.010+08:00| str| 110.0| 10.0|
+-----------------------------+---------------------+--------------------+-----------------------------+
</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 class="line-number"></div><div class="line-number"></div></div></div><p>Sql:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;x -&gt; {x + x}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl1<span class="token punctuation">,</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;x -&gt; {x * 3}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl2<span class="token punctuation">,</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;x -&gt; {x * x}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl3<span class="token punctuation">,</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;x -&gt; {multiply(x, 100)}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl4<span class="token punctuation">,</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> st<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;(x, y) -&gt; {x + y}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl5<span class="token punctuation">,</span> jexl<span class="token punctuation">(</span>temperature<span class="token punctuation">,</span> st<span class="token punctuation">,</span> str<span class="token punctuation">,</span> <span class="token string">&#39;expr&#39;</span><span class="token operator">=</span><span class="token string">&#39;(x, y, z) -&gt; {x + y + z}&#39;</span><span class="token punctuation">)</span> <span class="token keyword">as</span> jexl6 <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><span class="token identifier"><span class="token punctuation">\`</span><span class="token punctuation">\`</span></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|jexl1|jexl2|jexl3| jexl4|jexl5| jexl6|
+-----------------------------+-----+-----+-----+------+-----+--------+
|1970-01-01T08:00:00.000+08:00| 0.0| 0.0| 0.0| 0.0| 10.0| 10.0str|
|1970-01-01T08:00:00.001+08:00| 2.0| 3.0| 1.0| 100.0| 21.0| 21.0str|
|1970-01-01T08:00:00.002+08:00| 4.0| 6.0| 4.0| 200.0| 32.0| 32.0str|
|1970-01-01T08:00:00.003+08:00| 6.0| 9.0| 9.0| 300.0| 43.0| 43.0str|
|1970-01-01T08:00:00.004+08:00| 8.0| 12.0| 16.0| 400.0| 54.0| 54.0str|
|1970-01-01T08:00:00.005+08:00| 10.0| 15.0| 25.0| 500.0| 65.0| 65.0str|
|1970-01-01T08:00:00.006+08:00| 12.0| 18.0| 36.0| 600.0| 76.0| 76.0str|
|1970-01-01T08:00:00.007+08:00| 14.0| 21.0| 49.0| 700.0| 87.0| 87.0str|
|1970-01-01T08:00:00.008+08:00| 16.0| 24.0| 64.0| 800.0| 98.0| 98.0str|
|1970-01-01T08:00:00.009+08:00| 18.0| 27.0| 81.0| 900.0|109.0|109.0str|
|1970-01-01T08:00:00.010+08:00| 20.0| 30.0|100.0|1000.0|120.0|120.0str|
+-----------------------------+-----+-----+-----+------+-----+--------+
Total line number = 11
It costs 0.118s
</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 class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div>`,8);function x(k,h){const e=t("ExternalLinkIcon");return i(),o("div",null,[r(`
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`),d,u,n("p",null,[s("Java Expression Language (JEXL) is an expression language engine. We use JEXL to extend UDFs, which are implemented on the command line with simple lambda expressions. See the link for "),n("a",m,[s("operators supported in jexl lambda expressions"),l(e)]),s(".")]),v])}const g=a(c,[["render",x],["__file","Lambda.html.vue"]]);export{g as default};