| import{_ as s,o as n,c as a,e}from"./app-Bx8hKGcu.js";const t={},p=e(`<h2 id="标识符" tabindex="-1"><a class="header-anchor" href="#标识符"><span>标识符</span></a></h2><h3 id="使用场景" tabindex="-1"><a class="header-anchor" href="#使用场景"><span>使用场景</span></a></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"><span>约束</span></a></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"><span>如何在反引号引起的标识符中使用引号</span></a></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" data-title="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"><span>特殊情况示例</span></a></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" data-title="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" data-title="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" data-title="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" data-title="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" data-title="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" data-title="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" data-title="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></ul>`,16),i=[p];function l(o,c){return n(),a("div",null,i)}const d=s(t,[["render",l],["__file","Identifier.html.vue"]]),u=JSON.parse('{"path":"/zh/UserGuide/V1.1.x/Syntax-Conventions/Identifier.html","title":"","lang":"zh-CN","frontmatter":{"description":"标识符 使用场景 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。 约束 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。 标识符命名有以下约束： ...","head":[["link",{"rel":"alternate","hreflang":"en-us","href":"https://iotdb.apache.org/UserGuide/V1.1.x/Syntax-Conventions/Identifier.html"}],["meta",{"property":"og:url","content":"https://iotdb.apache.org/zh/UserGuide/V1.1.x/Syntax-Conventions/Identifier.html"}],["meta",{"property":"og:site_name","content":"IoTDB Website"}],["meta",{"property":"og:description","content":"标识符 使用场景 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。 约束 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。 标识符命名有以下约束： ..."}],["meta",{"property":"og:type","content":"article"}],["meta",{"property":"og:locale","content":"zh-CN"}],["meta",{"property":"og:locale:alternate","content":"en-US"}],["meta",{"property":"og:updated_time","content":"2023-07-10T03:11:17.000Z"}],["meta",{"property":"article:modified_time","content":"2023-07-10T03:11:17.000Z"}],["script",{"type":"application/ld+json"},"{\\"@context\\":\\"https://schema.org\\",\\"@type\\":\\"Article\\",\\"headline\\":\\"\\",\\"image\\":[\\"\\"],\\"dateModified\\":\\"2023-07-10T03:11:17.000Z\\",\\"author\\":[]}"]]},"headers":[{"level":2,"title":"标识符","slug":"标识符","link":"#标识符","children":[{"level":3,"title":"使用场景","slug":"使用场景","link":"#使用场景","children":[]},{"level":3,"title":"约束","slug":"约束","link":"#约束","children":[]},{"level":3,"title":"如何在反引号引起的标识符中使用引号","slug":"如何在反引号引起的标识符中使用引号","link":"#如何在反引号引起的标识符中使用引号","children":[]},{"level":3,"title":"特殊情况示例","slug":"特殊情况示例","link":"#特殊情况示例","children":[]}]}],"git":{"createdTime":1688958677000,"updatedTime":1688958677000,"contributors":[{"name":"CritasWang","email":"critas@outlook.com","commits":1}]},"readingTime":{"minutes":3.29,"words":987},"filePathRelative":"zh/UserGuide/V1.1.x/Syntax-Conventions/Identifier.md","localizedDate":"2023年7月10日","autoDesc":true}');export{d as comp,u as data}; |
