| import{_ as a,r as s,o as t,c as i,a as r,d as o,e,b as d,w as l,f as c}from"./app-LsTKUu1f.js";const p={},u=c(`<h1 id="query-alignment-mode" tabindex="-1"><a class="header-anchor" href="#query-alignment-mode" aria-hidden="true">#</a> Query Alignment Mode</h1><p>In addition, IoTDB supports another result set format: <code>ALIGN BY DEVICE</code>.</p><h2 id="align-by-device" tabindex="-1"><a class="header-anchor" href="#align-by-device" aria-hidden="true">#</a> align by device</h2><p>The <code>ALIGN BY DEVICE</code> indicates that the deviceId is considered as a column. Therefore, there are totally limited columns in the dataset.</p><blockquote><p>NOTE：</p><p>1.You can see the result of 'align by device' as one relational table, <code>Time + Device</code> is the primary key of this Table.</p><p>2.The result is order by <code>Device</code> firstly, and then by <code>Time</code> order.</p></blockquote><p>The SQL statement is:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> <span class="token operator">*</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token operator">*</span> <span class="token keyword">where</span> <span class="token keyword">time</span> <span class="token operator"><=</span> <span class="token number">2017</span><span class="token operator">-</span><span class="token number">11</span><span class="token operator">-</span><span class="token number">01</span>T00:<span class="token number">01</span>:<span class="token number">00</span> align <span class="token keyword">by</span> device<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>The result shows below:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+-----------------+-----------+------+--------+ |
| | Time| Device|temperature|status|hardware| |
| +-----------------------------+-----------------+-----------+------+--------+ |
| |2017-11-01T00:00:00.000+08:00|root.ln.wf01.wt01| 25.96| true| null| |
| |2017-11-01T00:01:00.000+08:00|root.ln.wf01.wt01| 24.36| true| null| |
| |1970-01-01T08:00:00.001+08:00|root.ln.wf02.wt02| null| true| v1| |
| |1970-01-01T08:00:00.002+08:00|root.ln.wf02.wt02| null| false| v2| |
| |2017-11-01T00:00:00.000+08:00|root.ln.wf02.wt02| null| true| v2| |
| |2017-11-01T00:01:00.000+08:00|root.ln.wf02.wt02| null| true| v2| |
| +-----------------------------+-----------------+-----------+------+--------+ |
| Total line number = 6 |
| It costs 0.012s |
| </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></div><h2 id="ordering-in-align-by-device" tabindex="-1"><a class="header-anchor" href="#ordering-in-align-by-device" aria-hidden="true">#</a> Ordering in ALIGN BY DEVICE</h2><p>ALIGN BY DEVICE mode arranges according to the device first, and sort each device in ascending order according to the timestamp. The ordering and priority can be adjusted through <code>ORDER BY</code> clause.</p>`,11);function h(m,v){const n=s("RouterLink");return t(),i("div",null,[r(` |
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| `),u,o("p",null,[e("For details and examples, see the document "),d(n,{to:"/UserGuide/Master/stage/Query-Data/Order-By.html"},{default:l(()=>[e("Order By")]),_:1}),e(".")])])}const g=a(p,[["render",h],["__file","Align-By.html.vue"]]);export{g as default}; |
