| import{_ as d,C as t,O as l,P as r,ah as c,Q as o,U as e,ai as a,ae as i,aW as s}from"./framework-62ad666a.js";const v={},u=s(`<h1 id="元数据操作" tabindex="-1"><a class="header-anchor" href="#元数据操作" aria-hidden="true">#</a> 元数据操作</h1><h2 id="数据库管理" tabindex="-1"><a class="header-anchor" href="#数据库管理" aria-hidden="true">#</a> 数据库管理</h2><p>数据库(Database)可以被视为关系数据库中的Database。</p><h3 id="创建数据库" tabindex="-1"><a class="header-anchor" href="#创建数据库" aria-hidden="true">#</a> 创建数据库</h3><p>我们可以根据存储模型建立相应的数据库。如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB > CREATE DATABASE root.ln |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>需要注意的是,database 的父子节点都不能再设置 database。例如在已经有<code>root.ln</code>和<code>root.sgcc</code>这两个 database 的情况下,创建<code>root.ln.wf01</code> database 是不可行的。系统将给出相应的错误提示,如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> CREATE DATABASE root.ln.wf01 |
| Msg: 300: root.ln has already been created as database. |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><p>Database 节点名只支持中英文字符、数字、下划线的组合,如果想设置为纯数字或者包含其他字符,需要用反引号(\`\`)把 database 名称引起来。</p><p>还需注意,如果在 Windows 系统上部署,database 名是大小写不敏感的。例如同时创建<code>root.ln</code> 和 <code>root.LN</code> 是不被允许的。</p><h3 id="查看数据库" tabindex="-1"><a class="header-anchor" href="#查看数据库" aria-hidden="true">#</a> 查看数据库</h3>`,11),b=s(`<div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> show databases |
| IoTDB> show databases root.* |
| IoTDB> show databases root.** |
| </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><p>执行结果为:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-------------+----+-------------------------+-----------------------+-----------------------+ |
| | database| ttl|schema_replication_factor|data_replication_factor|time_partition_interval| |
| +-------------+----+-------------------------+-----------------------+-----------------------+ |
| | root.sgcc|null| 2| 2| 604800| |
| | root.ln|null| 2| 2| 604800| |
| +-------------+----+-------------------------+-----------------------+-----------------------+ |
| Total line number = 2 |
| It costs 0.060s |
| </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><h3 id="删除数据库" tabindex="-1"><a class="header-anchor" href="#删除数据库" aria-hidden="true">#</a> 删除数据库</h3><p>用户可以使用<code>DELETE DATABASE <PathPattern></code>语句删除该路径模式匹配的所有的数据库。在删除的过程中,需要注意的是数据库的数据也会被删除。</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB > DELETE DATABASE root.ln |
| IoTDB > DELETE DATABASE root.sgcc |
| // 删除所有数据,时间序列以及数据库 |
| IoTDB > DELETE DATABASE root.** |
| </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></div><h3 id="统计数据库数量" tabindex="-1"><a class="header-anchor" href="#统计数据库数量" aria-hidden="true">#</a> 统计数据库数量</h3><p>用户可以使用<code>COUNT DATABASES <PathPattern></code>语句统计数据库的数量,允许指定<code>PathPattern</code> 用来统计匹配该<code>PathPattern</code> 的数据库的数量</p><p>SQL 语句如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> show databases |
| IoTDB> count databases |
| IoTDB> count databases root.* |
| IoTDB> count databases root.sgcc.* |
| IoTDB> count databases root.sgcc |
| </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><p>执行结果为:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-------------+ |
| | database| |
| +-------------+ |
| | root.sgcc| |
| | root.turbine| |
| | root.ln| |
| +-------------+ |
| Total line number = 3 |
| It costs 0.003s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 3| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.003s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 3| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 0| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| |
| +-------------+ |
| | database| |
| +-------------+ |
| | 1| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| </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 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 class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div>`,12);function m(h,g){const n=t("RouterLink");return l(),r("div",null,[c(` |
| |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| |
| `),u,o("p",null,[e("在 database 创建后,我们可以使用 "),a(n,{to:"/zh/UserGuide/Master/Reference/SQL-Reference.html"},{default:i(()=>[e("SHOW DATABASES")]),_:1}),e(" 语句和 "),a(n,{to:"/zh/UserGuide/Master/Reference/SQL-Reference.html"},{default:i(()=>[e("SHOW DATABASES <PathPattern>")]),_:1}),e(" 来查看 database,SQL 语句如下所示:")]),b])}const T=d(v,[["render",m],["__file","Database.html.vue"]]);export{T as default}; |