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end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable active"><!----><span class="title">数据查询</span><span class="arrow down"></span></button><ul class="sidebar-links"><li><!--[--><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html" class="router-link-active router-link-exact-active nav-link active sidebar-link sidebar-page active" aria-label="概述"><!---->概述<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html#概述" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="概述"><!---->概述<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html#语法定义" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="语法定义"><!---->语法定义<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html#语法说明" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="语法说明"><!---->语法说明<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html#sql-示例" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="SQL 示例"><!---->SQL 示例<!----></a><ul class="sidebar-sub-headers"></ul></li><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/Master/Query-Data/Overview.html#查询执行接口" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="查询执行接口"><!---->查询执行接口<!----></a><ul class="sidebar-sub-headers"></ul></li></ul></li></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Select-Expression.html" class="nav-link sidebar-link sidebar-page" aria-label="选择表达式"><!---->选择表达式<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Last-Query.html" class="nav-link sidebar-link sidebar-page" aria-label="最新点查询"><!---->最新点查询<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Align-By.html" class="nav-link sidebar-link sidebar-page" aria-label="查询对齐模式"><!---->查询对齐模式<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Where-Condition.html" class="nav-link sidebar-link sidebar-page" aria-label="查询过滤条件"><!---->查询过滤条件<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Group-By.html" class="nav-link sidebar-link sidebar-page" aria-label="分段分组聚合"><!---->分段分组聚合<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Having-Condition.html" class="nav-link sidebar-link sidebar-page" aria-label="聚合结果过滤"><!---->聚合结果过滤<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Fill.html" class="nav-link sidebar-link sidebar-page" aria-label="结果集补空值"><!---->结果集补空值<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Pagination.html" class="nav-link sidebar-link sidebar-page" aria-label="结果集分页"><!---->结果集分页<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Select-Into.html" class="nav-link sidebar-link sidebar-page" aria-label="查询写回"><!---->查询写回<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/Master/Query-Data/Continuous-Query.html" class="nav-link sidebar-link sidebar-page" aria-label="连续查询"><!---->连续查询<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li></ul></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">运算符和函数</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">触发器</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">监控告警</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">权限管理</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">运维工具</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">端云协同</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">系统集成</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">分布式</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">FAQ</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">参考</span><span class="arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main class="page" id="main-content"><!--[--><!----><nav class="breadcrumb disable"></nav><div 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--><h1 id="数据查询" tabindex="-1"><a class="header-anchor" href="#数据查询" aria-hidden="true">#</a> 数据查询</h1><h2 id="概述" tabindex="-1"><a class="header-anchor" href="#概述" aria-hidden="true">#</a> 概述</h2><p>在 IoTDB 中,使用 <code>SELECT</code> 语句从一条或多条时间序列中查询数据。</p><h3 id="语法定义" tabindex="-1"><a class="header-anchor" href="#语法定义" aria-hidden="true">#</a> 语法定义</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 punctuation">[</span><span class="token keyword">LAST</span><span class="token punctuation">]</span> selectExpr <span class="token punctuation">[</span><span class="token punctuation">,</span> selectExpr<span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token punctuation">[</span><span class="token keyword">INTO</span> intoItem <span class="token punctuation">[</span><span class="token punctuation">,</span> intoItem<span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<span class="token keyword">FROM</span> prefixPath <span class="token punctuation">[</span><span class="token punctuation">,</span> prefixPath<span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token punctuation">[</span><span class="token keyword">WHERE</span> whereCondition<span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">GROUP</span> <span class="token keyword">BY</span> {
<span class="token punctuation">(</span><span class="token punctuation">[</span>startTime<span class="token punctuation">,</span> endTime<span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token keyword">interval</span> <span class="token punctuation">[</span><span class="token punctuation">,</span> slidingStep<span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token operator">|</span>
<span class="token keyword">LEVEL</span> <span class="token operator">=</span> levelNum <span class="token punctuation">[</span><span class="token punctuation">,</span> levelNum<span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token operator">|</span>
TAGS<span class="token punctuation">(</span>tagKey <span class="token punctuation">[</span><span class="token punctuation">,</span> tagKey<span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token operator">|</span>
VARIATION<span class="token punctuation">(</span>expression<span class="token punctuation">[</span><span class="token punctuation">,</span>delta<span class="token punctuation">]</span><span class="token punctuation">[</span><span class="token punctuation">,</span>ignoreNull<span class="token operator">=</span><span class="token boolean">true</span><span class="token operator">/</span><span class="token boolean">false</span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token operator">|</span>
CONDITION<span class="token punctuation">(</span>expression<span class="token punctuation">,</span><span class="token punctuation">[</span>keep<span class="token operator">&gt;</span><span class="token operator">/</span><span class="token operator">&gt;=</span><span class="token operator">/</span><span class="token operator">=</span><span class="token operator">/</span><span class="token operator">&lt;</span><span class="token operator">/</span><span class="token operator">&lt;=</span><span class="token punctuation">]</span>threshold<span class="token punctuation">[</span><span class="token punctuation">,</span>ignoreNull<span class="token operator">=</span><span class="token boolean">true</span><span class="token operator">/</span><span class="token boolean">false</span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token operator">|</span>
<span class="token keyword">SESSION</span><span class="token punctuation">(</span>timeInterval<span class="token punctuation">)</span> <span class="token operator">|</span>
<span class="token function">COUNT</span><span class="token punctuation">(</span>expression<span class="token punctuation">,</span> size<span class="token punctuation">[</span><span class="token punctuation">,</span>ignoreNull<span class="token operator">=</span><span class="token boolean">true</span><span class="token operator">/</span><span class="token boolean">false</span><span class="token punctuation">]</span><span class="token punctuation">)</span>
}<span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">HAVING</span> havingCondition<span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ORDER</span> <span class="token keyword">BY</span> sortKey {<span class="token keyword">ASC</span> <span class="token operator">|</span> <span class="token keyword">DESC</span>}<span class="token punctuation">]</span>
<span class="token punctuation">[</span>FILL <span class="token punctuation">(</span>{PREVIOUS <span class="token operator">|</span> LINEAR <span class="token operator">|</span> constant}<span class="token punctuation">)</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span>SLIMIT seriesLimit<span class="token punctuation">]</span> <span class="token punctuation">[</span>SOFFSET seriesOffset<span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">LIMIT</span> rowLimit<span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">OFFSET</span> rowOffset<span class="token punctuation">]</span>
<span class="token punctuation">[</span>ALIGN <span class="token keyword">BY</span> {<span class="token keyword">TIME</span> <span class="token operator">|</span> DEVICE}<span class="token punctuation">]</span>
</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 class="line-number"></div><div class="line-number"></div></div></div><h3 id="语法说明" tabindex="-1"><a class="header-anchor" href="#语法说明" aria-hidden="true">#</a> 语法说明</h3><h4 id="select-子句" tabindex="-1"><a class="header-anchor" href="#select-子句" aria-hidden="true">#</a> <code>SELECT</code> 子句</h4><ul><li><code>SELECT</code> 子句指定查询的输出,由若干个 <code>selectExpr</code> 组成。</li><li>每个 <code>selectExpr</code> 定义查询结果中的一列或多列,它是一个由时间序列路径后缀、常量、函数和运算符组成的表达式。</li><li>支持使用<code>AS</code>为查询结果集中的列指定别名。</li><li><code>SELECT</code> 子句中使用 <code>LAST</code> 关键词可以指定查询为最新点查询,详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Last-Query.html" class="">最新点查询</a></li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Select-Expression.html" class="">选择表达式</a></li></ul><h4 id="into-子句" tabindex="-1"><a class="header-anchor" href="#into-子句" aria-hidden="true">#</a> <code>INTO</code> 子句</h4><ul><li><code>SELECT INTO</code> 用于将查询结果写入一系列指定的时间序列中。<code>INTO</code> 子句指定了查询结果写入的目标时间序列。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Select-Into.html" class="">SELECT INTO(查询写回)</a></li></ul><h4 id="from-子句" tabindex="-1"><a class="header-anchor" href="#from-子句" aria-hidden="true">#</a> <code>FROM</code> 子句</h4><ul><li><code>FROM</code> 子句包含要查询的一个或多个时间序列的路径前缀,支持使用通配符。</li><li>在执行查询时,会将 <code>FROM</code> 子句中的路径前缀和 <code>SELECT</code> 子句中的后缀进行拼接得到完整的查询目标序列。</li></ul><h4 id="where-子句" tabindex="-1"><a class="header-anchor" href="#where-子句" aria-hidden="true">#</a> <code>WHERE</code> 子句</h4><ul><li><code>WHERE</code> 子句指定了对数据行的筛选条件,由一个 <code>whereCondition</code> 组成。</li><li><code>whereCondition</code> 是一个逻辑表达式,对于要选择的每一行,其计算结果为真。如果没有 <code>WHERE</code> 子句,将选择所有行。</li><li><code>whereCondition</code> 中,可以使用除聚合函数之外的任何 IOTDB 支持的函数和运算符。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Where-Condition.html" class="">查询过滤条件</a></li></ul><h4 id="group-by-子句" tabindex="-1"><a class="header-anchor" href="#group-by-子句" aria-hidden="true">#</a> <code>GROUP BY</code> 子句</h4><ul><li><code>GROUP BY</code> 子句指定对序列进行分段或分组聚合的方式。</li><li>分段聚合是指按照时间维度,针对同时间序列中不同数据点之间的时间关系,对数据在行的方向进行分段,每个段得到一个聚合值。目前支持<strong>时间区间分段</strong><strong>差值分段</strong><strong>条件分段</strong><strong>会话分段</strong><strong>点数分段</strong>,未来将支持更多分段方式。</li><li>分组聚合是指针对不同时间序列,在时间序列的潜在业务属性上分组,每个组包含若干条时间序列,每个组得到一个聚合值。支持<strong>按路径层级分组</strong><strong>按序列标签分组</strong>两种分组方式。</li><li>分段聚合和分组聚合可以混合使用。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Group-By.html" class="">分段分组聚合</a></li></ul><h4 id="having-子句" tabindex="-1"><a class="header-anchor" href="#having-子句" aria-hidden="true">#</a> <code>HAVING</code> 子句</h4><ul><li><code>HAVING</code> 子句指定了对聚合结果的筛选条件,由一个 <code>havingCondition</code> 组成。</li><li><code>havingCondition</code> 是一个逻辑表达式,对于要选择的聚合结果,其计算结果为真。如果没有 <code>HAVING</code> 子句,将选择所有聚合结果。</li><li><code>HAVING</code> 要和聚合函数以及 <code>GROUP BY</code> 子句一起使用。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Having-Condition.html" class="">聚合结果过滤</a></li></ul><h4 id="order-by-子句" tabindex="-1"><a class="header-anchor" href="#order-by-子句" aria-hidden="true">#</a> <code>ORDER BY</code> 子句</h4><ul><li><code>ORDER BY</code> 子句用于指定结果集的排序方式。</li><li>按时间对齐模式下:默认按照时间戳大小升序排列,可以通过 <code>ORDER BY TIME DESC</code> 指定结果集按照时间戳大小降序排列。</li><li>按设备对齐模式下:默认按照设备名的字典序升序排列,每个设备内部按照时间戳大小升序排列,可以通过 <code>ORDER BY</code> 子句调整设备列和时间列的排序优先级。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Order-By.html" class="">结果集排序</a></li></ul><h4 id="fill-子句" tabindex="-1"><a class="header-anchor" href="#fill-子句" aria-hidden="true">#</a> <code>FILL</code> 子句</h4><ul><li><code>FILL</code> 子句用于指定数据缺失情况下的填充模式,允许用户按照特定的方法对任何查询的结果集填充空值。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Fill.html" class="">结果集补空值</a></li></ul><h4 id="slimit-和-soffset-子句" tabindex="-1"><a class="header-anchor" href="#slimit-和-soffset-子句" aria-hidden="true">#</a> <code>SLIMIT</code><code>SOFFSET</code> 子句</h4><ul><li><code>SLIMIT</code> 指定查询结果的列数,<code>SOFFSET</code> 指定查询结果显示的起始列位置。<code>SLIMIT</code><code>SOFFSET</code> 仅用于控制值列,对时间列和设备列无效。</li><li>关于查询结果分页,详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Pagination.html" class="">结果集分页</a></li></ul><h4 id="limit-和-offset-子句" tabindex="-1"><a class="header-anchor" href="#limit-和-offset-子句" aria-hidden="true">#</a> <code>LIMIT</code><code>OFFSET</code> 子句</h4><ul><li><code>LIMIT</code> 指定查询结果的行数,<code>OFFSET</code> 指定查询结果显示的起始行位置。</li><li>关于查询结果分页,详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Pagination.html" class="">结果集分页</a></li></ul><h4 id="align-by-子句" tabindex="-1"><a class="header-anchor" href="#align-by-子句" aria-hidden="true">#</a> <code>ALIGN BY</code> 子句</h4><ul><li>查询结果集默认<strong>按时间对齐</strong>,包含一列时间列和若干个值列,每一行数据各列的时间戳相同。</li><li>除按时间对齐之外,还支持<strong>按设备对齐</strong>,查询结果集包含一列时间列、一列设备列和若干个值列。</li><li>详细说明及示例见文档 <a href="/zh/UserGuide/Master/Query-Data/Align-By.html" class="">查询对齐模式</a></li></ul><h3 id="sql-示例" tabindex="-1"><a class="header-anchor" href="#sql-示例" aria-hidden="true">#</a> SQL 示例</h3><h4 id="示例1-根据一个时间区间选择一列数据" tabindex="-1"><a class="header-anchor" href="#示例1-根据一个时间区间选择一列数据" aria-hidden="true">#</a> 示例1:根据一个时间区间选择一列数据</h4><p>SQL 语句为:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> temperature <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 keyword">where</span> <span class="token keyword">time</span> <span class="token operator">&lt;</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">08</span>:<span class="token number">00.000</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>其含义为:</p><p>被选择的设备为 ln 集团 wf01 子站 wt01 设备;被选择的时间序列为温度传感器(temperature);该语句要求选择出该设备在 “2017-11-01T00:08:00.000” 时间点以前的所有温度传感器的值。</p><p>该 SQL 语句的执行结果如下:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+-----------------------------+
| Time|root.ln.wf01.wt01.temperature|
+-----------------------------+-----------------------------+
|2017-11-01T00:00:00.000+08:00| 25.96|
|2017-11-01T00:01:00.000+08:00| 24.36|
|2017-11-01T00:02:00.000+08:00| 20.09|
|2017-11-01T00:03:00.000+08:00| 20.18|
|2017-11-01T00:04:00.000+08:00| 21.13|
|2017-11-01T00:05:00.000+08:00| 22.72|
|2017-11-01T00:06:00.000+08:00| 20.71|
|2017-11-01T00:07:00.000+08:00| 21.45|
+-----------------------------+-----------------------------+
Total line number = 8
It costs 0.026s
</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="示例2-根据一个时间区间选择多列数据" tabindex="-1"><a class="header-anchor" href="#示例2-根据一个时间区间选择多列数据" aria-hidden="true">#</a> 示例2:根据一个时间区间选择多列数据</h4><p>SQL 语句为:</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 keyword">status</span><span class="token punctuation">,</span> temperature <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 keyword">where</span> <span class="token keyword">time</span> <span class="token operator">&gt;</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">05</span>:<span class="token number">00.000</span> <span class="token operator">and</span> <span class="token keyword">time</span> <span class="token operator">&lt;</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">12</span>:<span class="token number">00.000</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>其含义为:</p><p>被选择的设备为 ln 集团 wf01 子站 wt01 设备;被选择的时间序列为供电状态(status)和温度传感器(temperature);该语句要求选择出 “2017-11-01T00:05:00.000” 至 “2017-11-01T00:12:00.000” 之间的所选时间序列的值。</p><p>该 SQL 语句的执行结果如下:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
| Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
+-----------------------------+------------------------+-----------------------------+
|2017-11-01T00:06:00.000+08:00| false| 20.71|
|2017-11-01T00:07:00.000+08:00| false| 21.45|
|2017-11-01T00:08:00.000+08:00| false| 22.58|
|2017-11-01T00:09:00.000+08:00| false| 20.98|
|2017-11-01T00:10:00.000+08:00| true| 25.52|
|2017-11-01T00:11:00.000+08:00| false| 22.91|
+-----------------------------+------------------------+-----------------------------+
Total line number = 6
It costs 0.018s
</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><h4 id="示例3-按照多个时间区间选择同一设备的多列数据" tabindex="-1"><a class="header-anchor" href="#示例3-按照多个时间区间选择同一设备的多列数据" aria-hidden="true">#</a> 示例3:按照多个时间区间选择同一设备的多列数据</h4><p>IoTDB 支持在一次查询中指定多个时间区间条件,用户可以根据需求随意组合时间区间条件。例如,</p><p>SQL 语句为:</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 keyword">status</span><span class="token punctuation">,</span> temperature <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 keyword">where</span> <span class="token punctuation">(</span><span class="token keyword">time</span> <span class="token operator">&gt;</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">05</span>:<span class="token number">00.000</span> <span class="token operator">and</span> <span class="token keyword">time</span> <span class="token operator">&lt;</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">12</span>:<span class="token number">00.000</span><span class="token punctuation">)</span> <span class="token operator">or</span> <span class="token punctuation">(</span><span class="token keyword">time</span> <span class="token operator">&gt;=</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>T16:<span class="token number">35</span>:<span class="token number">00.000</span> <span class="token operator">and</span> <span class="token keyword">time</span> <span class="token operator">&lt;=</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>T16:<span class="token number">37</span>:<span class="token number">00.000</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>其含义为:</p><p>被选择的设备为 ln 集团 wf01 子站 wt01 设备;被选择的时间序列为“供电状态(status)”和“温度传感器(temperature)”;该语句指定了两个不同的时间区间,分别为“2017-11-01T00:05:00.000 至 2017-11-01T00:12:00.000”和“2017-11-01T16:35:00.000 至 2017-11-01T16:37:00.000”;该语句要求选择出满足任一时间区间的被选时间序列的值。</p><p>该 SQL 语句的执行结果如下:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+------------------------+-----------------------------+
| Time|root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|
+-----------------------------+------------------------+-----------------------------+
|2017-11-01T00:06:00.000+08:00| false| 20.71|
|2017-11-01T00:07:00.000+08:00| false| 21.45|
|2017-11-01T00:08:00.000+08:00| false| 22.58|
|2017-11-01T00:09:00.000+08:00| false| 20.98|
|2017-11-01T00:10:00.000+08:00| true| 25.52|
|2017-11-01T00:11:00.000+08:00| false| 22.91|
|2017-11-01T16:35:00.000+08:00| true| 23.44|
|2017-11-01T16:36:00.000+08:00| false| 21.98|
|2017-11-01T16:37:00.000+08:00| false| 21.93|
+-----------------------------+------------------------+-----------------------------+
Total line number = 9
It costs 0.018s
</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></div><h4 id="示例4-按照多个时间区间选择不同设备的多列数据" tabindex="-1"><a class="header-anchor" href="#示例4-按照多个时间区间选择不同设备的多列数据" aria-hidden="true">#</a> 示例4:按照多个时间区间选择不同设备的多列数据</h4><p>该系统支持在一次查询中选择任意列的数据,也就是说,被选择的列可以来源于不同的设备。例如,SQL 语句为:</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token keyword">select</span> wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">.</span><span class="token keyword">status</span><span class="token punctuation">,</span> wf02<span class="token punctuation">.</span>wt02<span class="token punctuation">.</span>hardware <span class="token keyword">from</span> root<span class="token punctuation">.</span>ln <span class="token keyword">where</span> <span class="token punctuation">(</span><span class="token keyword">time</span> <span class="token operator">&gt;</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">05</span>:<span class="token number">00.000</span> <span class="token operator">and</span> <span class="token keyword">time</span> <span class="token operator">&lt;</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">12</span>:<span class="token number">00.000</span><span class="token punctuation">)</span> <span class="token operator">or</span> <span class="token punctuation">(</span><span class="token keyword">time</span> <span class="token operator">&gt;=</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>T16:<span class="token number">35</span>:<span class="token number">00.000</span> <span class="token operator">and</span> <span class="token keyword">time</span> <span class="token operator">&lt;=</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>T16:<span class="token number">37</span>:<span class="token number">00.000</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>其含义为:</p><p>被选择的时间序列为 “ln 集团 wf01 子站 wt01 设备的供电状态” 以及 “ln 集团 wf02 子站 wt02 设备的硬件版本”;该语句指定了两个时间区间,分别为 “2017-11-01T00:05:00.000 至 2017-11-01T00:12:00.000” 和 “2017-11-01T16:35:00.000 至 2017-11-01T16:37:00.000”;该语句要求选择出满足任意时间区间的被选时间序列的值。</p><p>该 SQL 语句的执行结果如下:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+------------------------+--------------------------+
| Time|root.ln.wf01.wt01.status|root.ln.wf02.wt02.hardware|
+-----------------------------+------------------------+--------------------------+
|2017-11-01T00:06:00.000+08:00| false| v1|
|2017-11-01T00:07:00.000+08:00| false| v1|
|2017-11-01T00:08:00.000+08:00| false| v1|
|2017-11-01T00:09:00.000+08:00| false| v1|
|2017-11-01T00:10:00.000+08:00| true| v2|
|2017-11-01T00:11:00.000+08:00| false| v1|
|2017-11-01T16:35:00.000+08:00| true| v2|
|2017-11-01T16:36:00.000+08:00| false| v1|
|2017-11-01T16:37:00.000+08:00| false| v1|
+-----------------------------+------------------------+--------------------------+
Total line number = 9
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 class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="示例5-根据时间降序返回结果集" tabindex="-1"><a class="header-anchor" href="#示例5-根据时间降序返回结果集" aria-hidden="true">#</a> 示例5:根据时间降序返回结果集</h4><p>IoTDB 支持 <code>order by time</code> 语句,用于对结果按照时间进行降序展示。例如,SQL 语句为:</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">&gt;</span> <span class="token number">1</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> <span class="token keyword">limit</span> <span class="token number">10</span><span class="token punctuation">;</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>语句执行的结果为:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
| Time|root.ln.wf02.wt02.hardware|root.ln.wf02.wt02.status|root.ln.wf01.wt01.temperature|root.ln.wf01.wt01.status|
+-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
|2017-11-07T23:59:00.000+08:00| v1| false| 21.07| false|
|2017-11-07T23:58:00.000+08:00| v1| false| 22.93| false|
|2017-11-07T23:57:00.000+08:00| v2| true| 24.39| true|
|2017-11-07T23:56:00.000+08:00| v2| true| 24.44| true|
|2017-11-07T23:55:00.000+08:00| v2| true| 25.9| true|
|2017-11-07T23:54:00.000+08:00| v1| false| 22.52| false|
|2017-11-07T23:53:00.000+08:00| v2| true| 24.58| true|
|2017-11-07T23:52:00.000+08:00| v1| false| 20.18| false|
|2017-11-07T23:51:00.000+08:00| v1| false| 22.24| false|
|2017-11-07T23:50:00.000+08:00| v2| true| 23.7| true|
+-----------------------------+--------------------------+------------------------+-----------------------------+------------------------+
Total line number = 10
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 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><h3 id="查询执行接口" tabindex="-1"><a class="header-anchor" href="#查询执行接口" aria-hidden="true">#</a> 查询执行接口</h3><p>在 IoTDB 中,提供两种方式执行数据查询操作:</p><ul><li>使用 IoTDB-SQL 执行查询。</li><li>常用查询的高效执行接口,包括时间序列原始数据范围查询、最新点查询、简单聚合查询。</li></ul><h4 id="使用-iotdb-sql-执行查询" tabindex="-1"><a class="header-anchor" href="#使用-iotdb-sql-执行查询" aria-hidden="true">#</a> 使用 IoTDB-SQL 执行查询</h4><p>数据查询语句支持在 SQL 命令行终端、JDBC、JAVA / C++ / Python / Go 等编程语言 API、RESTful API 中使用。</p><ul><li><p>在 SQL 命令行终端中执行查询语句:启动 SQL 命令行终端,直接输入查询语句执行即可,详见 <a href="/zh/UserGuide/Master/QuickStart/Command-Line-Interface.html" class="">SQL 命令行终端</a></p></li><li><p>在 JDBC 中执行查询语句,详见 <a href="/zh/UserGuide/Master/API/Programming-JDBC.html" class="">JDBC</a></p></li><li><p>在 JAVA / C++ / Python / Go 等编程语言 API 中执行查询语句,详见应用编程接口一章相应文档。接口原型如下:</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeQueryStatement</span><span class="token punctuation">(</span><span class="token class-name">String</span> sql<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></li><li><p>在 RESTful API 中使用,详见 <a href="/zh/UserGuide/Master/API/RestServiceV1.html" class="">HTTP API V1</a> 或者 <a href="/zh/UserGuide/Master/API/RestServiceV2.html" class="">HTTP API V2</a></p></li></ul><h4 id="常用查询的高效执行接口" tabindex="-1"><a class="header-anchor" href="#常用查询的高效执行接口" aria-hidden="true">#</a> 常用查询的高效执行接口</h4><p>各编程语言的 API 为常用的查询提供了高效执行接口,可以省去 SQL 解析等操作的耗时。包括:</p><ul><li>时间序列原始数据范围查询: <ul><li>指定的查询时间范围为左闭右开区间,包含开始时间但不包含结束时间。</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeRawDataQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token keyword">long</span> startTime<span class="token punctuation">,</span> <span class="token keyword">long</span> endTime<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><ul><li>最新点查询: <ul><li>查询最后一条时间戳大于等于某个时间点的数据。</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeLastDataQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token keyword">long</span> lastTime<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><ul><li>聚合查询: <ul><li>支持指定查询时间范围。指定的查询时间范围为左闭右开区间,包含开始时间但不包含结束时间。</li><li>支持按照时间区间分段查询。</li></ul></li></ul><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
<span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span> <span class="token keyword">long</span> startTime<span class="token punctuation">,</span> <span class="token keyword">long</span> endTime<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
<span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span>
<span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span>
<span class="token keyword">long</span> startTime<span class="token punctuation">,</span>
<span class="token keyword">long</span> endTime<span class="token punctuation">,</span>
<span class="token keyword">long</span> interval<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">SessionDataSet</span> <span class="token function">executeAggregationQuery</span><span class="token punctuation">(</span>
<span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">&gt;</span></span> paths<span class="token punctuation">,</span>
<span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Aggregation</span><span class="token punctuation">&gt;</span></span> aggregations<span class="token punctuation">,</span>
<span class="token keyword">long</span> startTime<span class="token punctuation">,</span>
<span class="token keyword">long</span> endTime<span class="token punctuation">,</span>
<span class="token keyword">long</span> interval<span class="token punctuation">,</span>
<span class="token keyword">long</span> slidingStep<span class="token punctuation">)</span><span class="token punctuation">;</span>
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