mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-10 16:48:17 +08:00
7 lines
2.6 KiB
HTML
7 lines
2.6 KiB
HTML
<div class="m-bg">
|
||
<h1>SQL SELECT INTO 语句</h1>
|
||
<p class="intro">通过 SQL，您可以从一个表复制信息到另一个表。</p> <p class="intro">SELECT INTO 语句从一个表复制数据，然后把数据插入到另一个新表中。</p> <h2>SQL SELECT INTO 语句</h2> <p>SELECT INTO 语句从一个表复制数据，然后把数据插入到另一个新表中。</p> <h3>SQL SELECT INTO 语法</h3> <p>我们可以复制所有的列插入到新表中：</p> <div class="code notranslate"><pre><div> SELECT *<br/> INTO <em>newtable</em> [IN <em>externaldb</em>]<br/> FROM <em>table1;</em> </div></pre></div> <p>或者只复制希望的列插入到新表中：</p> <div class="code notranslate"><pre><div> SELECT <em>column_name(s)</em><br/> INTO <em>newtable</em> [IN <em>externaldb</em>]<br/> FROM <em>table1;</em> </div></pre></div> <br/><table class="lamp"><tr>
|
||
<th width="34"><span aria-hidden="true" class="g-bg glyphicon glyphicon-flag margin-l-5"></span></th> <td> <p><strong>提示：</strong>新表将会使用 SELECT 语句中定义的列名称和类型进行创建。您可以使用 AS 子句来应用新名称。</p> </td> </tr></table>
|
||
<h2>SQL SELECT INTO 实例</h2> <p>创建 Customers 的备份复件：</p> <div class="code notranslate"><pre><div> SELECT *<br/> INTO CustomersBackup2013<br/> FROM Customers;</div></pre></div> <p>请使用 IN 子句来复制表到另一个数据库中：</p> <div class="code notranslate"><pre><div> SELECT *<br/> INTO CustomersBackup2013 IN 'Backup.mdb'<br/> FROM Customers;</div></pre></div> <p>只复制一些列插入到新表中：</p> <div class="code notranslate"><pre><div> SELECT CustomerName, ContactName<br/> INTO CustomersBackup2013<br/> FROM Customers;</div></pre></div> <p>只复制德国的客户插入到新表中：</p> <div class="code notranslate"><pre><div> SELECT *<br/> INTO CustomersBackup2013<br/> FROM Customers<br/> WHERE Country='Germany';</div></pre></div> <p>复制多个表中的数据插入到新表中：</p> <div class="code notranslate"> <pre><div> SELECT Customers.CustomerName, Orders.OrderID<br/> INTO CustomersOrderBackup2013<br/> FROM Customers<br/> LEFT JOIN Orders<br/> ON Customers.CustomerID=Orders.CustomerID;</div></pre> </div> <p><strong>提示：</strong>SELECT INTO 语句可用于通过另一种模式创建一个新的空表。只需要添加促使查询没有数据返回的 WHERE 子句即可：</p> <div class="code notranslate"><pre><div class="auto-style1"> SELECT *<br/>INTO <em>newtable</em><br/>FROM <em>table1</em><br/>WHERE 1=0;</div></pre></div> <div class="text-center padding-10 margin-t-5">
|
||
</div>
|
||
</div> |