| import{_ as d,r as s,o,c as r,a as c,d as n,e,b as a,w as p,f as i}from"./app-z4N-28Th.js";const u={},v=i(`<h1 id="语法约定" tabindex="-1"><a class="header-anchor" href="#语法约定" aria-hidden="true">#</a> 语法约定</h1><h2 id="字面值常量" tabindex="-1"><a class="header-anchor" href="#字面值常量" aria-hidden="true">#</a> 字面值常量</h2><p>该部分对 IoTDB 中支持的字面值常量进行说明，包括字符串常量、数值型常量、时间戳常量、布尔型常量和空值。</p><h3 id="字符串常量" tabindex="-1"><a class="header-anchor" href="#字符串常量" aria-hidden="true">#</a> 字符串常量</h3><p>在 IoTDB 中，字符串是由<strong>单引号（<code>'</code>）或双引号（<code>"</code>）字符括起来的字符序列</strong>。示例如下：</p><div class="language-Plain%20Text line-numbers-mode" data-ext="Plain%20Text"><pre class="language-Plain%20Text"><code>'a string' |
| "another string" |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><h4 id="使用场景" tabindex="-1"><a class="header-anchor" href="#使用场景" aria-hidden="true">#</a> 使用场景</h4><ul><li><p><code>INSERT</code> 或者 <code>SELECT</code> 中用于表达 <code>TEXT</code> 类型数据的场景。</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code># insert 示例 |
| insert into root.ln.wf02.wt02(timestamp,hardware) values(1, 'v1') |
| insert into root.ln.wf02.wt02(timestamp,hardware) values(2, '\\\\') |
| |
| +-----------------------------+--------------------------+ |
| | Time|root.ln.wf02.wt02.hardware| |
| +-----------------------------+--------------------------+ |
| |1970-01-01T08:00:00.001+08:00| v1| |
| +-----------------------------+--------------------------+ |
| |1970-01-01T08:00:00.002+08:00| \\\\| |
| +-----------------------------+--------------------------+ |
| |
| # select 示例 |
| select code from root.sg1.d1 where code in ('string1', 'string2'); |
| </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></li><li><p><code>LOAD</code> / <code>REMOVE</code> / <code>SETTLE</code> 指令中的文件路径。</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code># load 示例 |
| LOAD 'examplePath' |
| |
| # remove 示例 |
| REMOVE 'examplePath' |
| |
| # SETTLE 示例 |
| SETTLE 'examplePath' |
| </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></div></li><li><p>用户密码。</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code># 示例，write_pwd 即为用户密码 |
| CREATE USER ln_write_user 'write_pwd' |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>触发器和 UDF 中的类全类名，示例如下：</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code># 触发器示例，AS 后使用字符串表示类全类名 |
| CREATE TRIGGER \`alert-listener-sg1d1s1\` |
| AFTER INSERT |
| ON root.sg1.d1.s1 |
| AS 'org.apache.iotdb.db.engine.trigger.example.AlertListener' |
| WITH ( |
| 'lo' = '0', |
| 'hi' = '100.0' |
| ) |
| |
| # UDF 示例，AS 后使用字符串表示类全类名 |
| CREATE FUNCTION example AS 'org.apache.iotdb.udf.UDTFExample' |
| </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></li><li><p>Select 子句中可以为结果集中的值指定别名，别名可以被定义为字符串或者标识符，示例如下：</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code>select s1 as 'temperature', s2 as 'speed' from root.ln.wf01.wt01; |
| |
| # 表头如下所示 |
| +-----------------------------+-----------|-----+ |
| | Time|temperature|speed| |
| +-----------------------------+-----------|-----+ |
| </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></div></li><li><p>用于表示键值对，键值对的键和值可以被定义成常量（包括字符串）或者标识符，具体请参考键值对章节。</p></li></ul><h4 id="如何在字符串内使用引号" tabindex="-1"><a class="header-anchor" href="#如何在字符串内使用引号" aria-hidden="true">#</a> 如何在字符串内使用引号</h4><ul><li>在单引号引起的字符串内，双引号无需特殊处理。同理，在双引号引起的字符串内，单引号无需特殊处理。</li><li>在单引号引起的字符串里，可以通过双写单引号来表示一个单引号，即单引号 ' 可以表示为 ''。</li><li>在双引号引起的字符串里，可以通过双写双引号来表示一个双引号，即双引号 " 可以表示为 ""。</li></ul><p>字符串内使用引号的示例如下：</p><div class="language-Plain%20Text line-numbers-mode" data-ext="Plain%20Text"><pre class="language-Plain%20Text"><code>'string' // string |
| '"string"' // "string" |
| '""string""' // ""string"" |
| '''string' // 'string |
| |
| "string" // string |
| "'string'" // 'string' |
| "''string''" // ''string'' |
| """string" // "string |
| </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></div><h3 id="数值型常量" tabindex="-1"><a class="header-anchor" href="#数值型常量" aria-hidden="true">#</a> 数值型常量</h3><p>数值型常量包括整型和浮点型。</p><p>整型常量是一个数字序列。可以以 <code>+</code> 或 <code>-</code> 开头表示正负。例如：<code>1</code>, <code>-1</code>。</p><p>带有小数部分或由科学计数法表示的为浮点型常量，例如：<code>.1</code>, <code>3.14</code>, <code>-2.23</code>, <code>+1.70</code>, <code>1.2E3</code>, <code>1.2E-3</code>, <code>-1.2E3</code>, <code>-1.2E-3</code>。</p><p>在 IoTDB 中，<code>INT32</code> 和 <code>INT64</code> 表示整数类型（计算是准确的），<code>FLOAT</code> 和 <code>DOUBLE</code> 表示浮点数类型（计算是近似的）。</p><p>在浮点上下文中可以使用整数，它会被解释为等效的浮点数。</p><h3 id="时间戳常量" tabindex="-1"><a class="header-anchor" href="#时间戳常量" aria-hidden="true">#</a> 时间戳常量</h3>`,19),m=i(`<p>特别地，<code>NOW()</code>表示语句开始执行时的服务端系统时间戳。</p><h3 id="布尔型常量" tabindex="-1"><a class="header-anchor" href="#布尔型常量" aria-hidden="true">#</a> 布尔型常量</h3><p>布尔值常量 <code>TRUE</code> 和 <code>FALSE</code> 分别等价于 <code>1</code> 和 <code>0</code>，它们对大小写不敏感。</p><h3 id="空值" tabindex="-1"><a class="header-anchor" href="#空值" aria-hidden="true">#</a> 空值</h3><p><code>NULL</code>值表示没有数据。<code>NULL</code>对大小写不敏感。</p><h2 id="标识符" tabindex="-1"><a class="header-anchor" href="#标识符" aria-hidden="true">#</a> 标识符</h2><h3 id="使用场景-1" tabindex="-1"><a class="header-anchor" href="#使用场景-1" aria-hidden="true">#</a> 使用场景</h3><p>在 IoTDB 中，触发器名称、UDF函数名、元数据模板名称、用户与角色名、连续查询标识、Pipe、PipeSink、键值对中的键和值、别名等可以作为标识符。</p><h3 id="约束" tabindex="-1"><a class="header-anchor" href="#约束" aria-hidden="true">#</a> 约束</h3><p>请注意，此处约束是标识符的通用约束，具体标识符可能还附带其它约束条件，如用户名限制字符数大于等于4，更严格的约束请参考具体标识符相关的说明文档。</p><p><strong>标识符命名有以下约束：</strong></p><ul><li><p>不使用反引号括起的标识符中，允许出现以下字符：</p><ul><li>[ 0-9 a-z A-Z _ ] （字母，数字，下划线）</li><li>['\\u2E80'..'\\u9FFF'] （UNICODE 中文字符）</li></ul></li><li><p>标识符允许使用数字开头、不使用反引号括起的标识符不能全部为数字。</p></li><li><p>标识符是大小写敏感的。</p></li><li><p>标识符允许为关键字。</p></li></ul><p><strong>如果出现如下情况，标识符需要使用反引号进行引用：</strong></p><ul><li>标识符包含不允许的特殊字符。</li><li>标识符为实数。</li></ul><h3 id="如何在反引号引起的标识符中使用引号" tabindex="-1"><a class="header-anchor" href="#如何在反引号引起的标识符中使用引号" aria-hidden="true">#</a> 如何在反引号引起的标识符中使用引号</h3><p><strong>在反引号引起的标识符中可以直接使用单引号和双引号。</strong></p><p><strong>在用反引号引用的标识符中，可以通过双写反引号的方式使用反引号，即 \` 可以表示为 \`\`</strong>，示例如下：</p><div class="language-SQL line-numbers-mode" data-ext="SQL"><pre class="language-SQL"><code># 创建模板 t1\`t |
| create schema template \`t1\`\`t\` |
| (temperature FLOAT encoding=RLE, status BOOLEAN encoding=PLAIN compression=SNAPPY) |
| |
| # 创建模板 t1't"t |
| create schema template \`t1't"t\` |
| (temperature FLOAT encoding=RLE, status BOOLEAN encoding=PLAIN compression=SNAPPY) |
| </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></div><h3 id="特殊情况示例" tabindex="-1"><a class="header-anchor" href="#特殊情况示例" aria-hidden="true">#</a> 特殊情况示例</h3><p>需要使用反引号进行引用的部分情况示例：</p><ul><li><p>触发器名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建触发器 alert.\`listener-sg1d1s1</span> |
| <span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <span class="token identifier"><span class="token punctuation">\`</span>alert.\`\`listener-sg1d1s1<span class="token punctuation">\`</span></span> |
| <span class="token keyword">AFTER</span> <span class="token keyword">INSERT</span> |
| <span class="token keyword">ON</span> root<span class="token punctuation">.</span>sg1<span class="token punctuation">.</span>d1<span class="token punctuation">.</span>s1 |
| <span class="token keyword">AS</span> <span class="token string">'org.apache.iotdb.db.engine.trigger.example.AlertListener'</span> |
| <span class="token keyword">WITH</span> <span class="token punctuation">(</span> |
| <span class="token string">'lo'</span> <span class="token operator">=</span> <span class="token string">'0'</span><span class="token punctuation">,</span> |
| <span class="token string">'hi'</span> <span class="token operator">=</span> <span class="token string">'100.0'</span> |
| <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></div></li><li><p>UDF 名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建名为 111 的 UDF，111 为实数，所以需要用反引号引用。</span> |
| <span class="token keyword">CREATE</span> <span class="token keyword">FUNCTION</span> <span class="token identifier"><span class="token punctuation">\`</span>111<span class="token punctuation">\`</span></span> <span class="token keyword">AS</span> <span class="token string">'org.apache.iotdb.udf.UDTFExample'</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div></li><li><p>元数据模板名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建名为 111 的元数据模板，111 为实数，需要用反引号引用。</span> |
| <span class="token keyword">create</span> <span class="token keyword">schema</span> template <span class="token identifier"><span class="token punctuation">\`</span>111<span class="token punctuation">\`</span></span> |
| <span class="token punctuation">(</span>temperature <span class="token keyword">FLOAT</span> encoding<span class="token operator">=</span>RLE<span class="token punctuation">,</span> <span class="token keyword">status</span> <span class="token keyword">BOOLEAN</span> encoding<span class="token operator">=</span>PLAIN compression<span class="token operator">=</span>SNAPPY<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></div></li><li><p>用户名、角色名出现上述特殊情况时需使用反引号引用，同时无论是否使用反引号引用，用户名、角色名中均不允许出现空格，具体请参考权限管理章节中的说明。</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建用户 special\`user.</span> |
| <span class="token keyword">CREATE</span> <span class="token keyword">USER</span> <span class="token identifier"><span class="token punctuation">\`</span>special\`\`user.<span class="token punctuation">\`</span></span> <span class="token string">'write_pwd'</span> |
| |
| <span class="token comment"># 创建角色 111</span> |
| <span class="token keyword">CREATE</span> ROLE <span class="token identifier"><span class="token punctuation">\`</span>111<span class="token punctuation">\`</span></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></div></li><li><p>连续查询标识出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建连续查询 test.cq</span> |
| <span class="token keyword">CREATE</span> CONTINUOUS QUERY <span class="token identifier"><span class="token punctuation">\`</span>test.cq<span class="token punctuation">\`</span></span> |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> max_value<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> temperature_max |
| <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 punctuation">.</span><span class="token operator">*</span> |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span> <span class="token keyword">time</span><span class="token punctuation">(</span><span class="token number">10</span>s<span class="token punctuation">)</span> |
| <span class="token keyword">END</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></div></li><li><p>Pipe、PipeSink 名称出现上述特殊情况时需使用反引号引用：</p><div class="language-sql line-numbers-mode" data-ext="sql"><pre class="language-sql"><code><span class="token comment"># 创建 PipeSink test.*1</span> |
| <span class="token keyword">CREATE</span> PIPESINK <span class="token identifier"><span class="token punctuation">\`</span>test.*1<span class="token punctuation">\`</span></span> <span class="token keyword">AS</span> IoTDB <span class="token punctuation">(</span><span class="token string">'ip'</span> <span class="token operator">=</span> <span class="token string">'输入你的IP'</span><span class="token punctuation">)</span> |
| |
| <span class="token comment"># 创建 Pipe test.*2</span> |
| <span class="token keyword">CREATE</span> PIPE <span class="token identifier"><span class="token punctuation">\`</span>test.*2<span class="token punctuation">\`</span></span> <span class="token keyword">TO</span> <span class="token identifier"><span class="token punctuation">\`</span>test.*1<span class="token punctuation">\`</span></span> <span class="token keyword">FROM</span> |
| <span class="token punctuation">(</span><span class="token keyword">select</span> <span class="token operator">*</span><span class="token operator">*</span> <span class="token keyword">from</span> root <span class="token keyword">WHERE</span> <span class="token keyword">time</span><span class="token operator">>=</span>yyyy<span class="token operator">-</span>mm<span class="token operator">-</span>dd HH:MM:SS<span class="token punctuation">)</span> <span class="token keyword">WITH</span> <span class="token string">'SyncDelOp'</span> <span class="token operator">=</span> <span class="token string">'true'</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></div></li><li><p>Select 子句中可以结果集中的值指定别名，别名可以被定义为字符串或者标识符，示例如下：</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 keyword">as</span> temperature<span class="token punctuation">,</span> s2 <span class="token keyword">as</span> speed <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 comment"># 表头如下所示</span> |
| <span class="token operator">+</span><span class="token comment">-----------------------------+-----------+-----+</span> |
| <span class="token operator">|</span> <span class="token keyword">Time</span><span class="token operator">|</span>temperature<span class="token operator">|</span>speed<span class="token operator">|</span> |
| <span class="token operator">+</span><span class="token comment">-----------------------------+-----------+-----+</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></div></li><li><p>用于表示键值对，键值对的键和值可以被定义成常量（包括字符串）或者标识符，具体请参考键值对章节。</p></li><li><p>路径中非database的节点允许含有“<em>”符号，在使用时需要把该节点用反引号括起来，如root.db.<code>*</code>，但是此种用法只建议在路径中不可避免含有“</em>”时使用。</p></li></ul><h2 id="关键字" tabindex="-1"><a class="header-anchor" href="#关键字" aria-hidden="true">#</a> 关键字</h2><p>关键字是在 SQL 具有特定含义的词，可以作为标识符。保留字是关键字的一个子集，保留字不能用于标识符。</p>`,23),k={href:"https://iotdb.apache.org/zh/UserGuide/Master/Reference/Keywords.html",target:"_blank",rel:"noopener noreferrer"},h=n("h2",{id:"词法与文法详细定义",tabindex:"-1"},[n("a",{class:"header-anchor",href:"#词法与文法详细定义","aria-hidden":"true"},"#"),e(" 词法与文法详细定义")],-1),b=n("p",null,"请阅读代码仓库中的词法和语法描述文件：",-1),g=n("p",null,[e("词法文件："),n("code",null,"antlr/src/main/antlr4/org/apache/iotdb/db/qp/sql/IoTDBSqlLexer.g4")],-1),w=n("p",null,[e("语法文件："),n("code",null,"antlr/src/main/antlr4/org/apache/iotdb/db/qp/sql/IoTDBSqlParser.g4")],-1);function E(T,S){const t=s("RouterLink"),l=s("ExternalLinkIcon");return o(),r("div",null,[c(` |
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| under the License. |
| |
| `),v,n("p",null,[e("时间戳是一个数据到来的时间点，在 IoTDB 中分为绝对时间戳和相对时间戳。详细信息可参考 "),a(t,{to:"/zh/UserGuide/Master/Basic-Concept/Data-Type.html"},{default:p(()=>[e("数据类型文档")]),_:1}),e("。")]),m,n("p",null,[e("关于 IoTDB 的关键字列表，可以查看 "),n("a",k,[e("关键字"),a(l)]),e(" 。")]),h,b,g,w])}const q=d(u,[["render",E],["__file","Syntax-Rule.html.vue"]]);export{q as default}; |
