MySQL将表a中查询的数据插入到表b中
如果表b存在
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<code class="sql"><code class="sql"><code class="sql">insert into b select * from a;</code></code></code> |
如果表b不存在
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<code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql">create table b as select * from a;</code></code></code></code></code></code> |
扩展:
将b表中的某写字段值插入到a表中
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<code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql">insert into a (userID,userName) select b.userID,b.userName from tr_ajax_chat_messages;</code></code></code></code></code></code></code></code></code></code></code> |
将a表和b表userID相等的值保存到a表
1<code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql"><code class="sql">update a set a.userName=(select b.userName from b where a.userID = b.userID);</code></code></code></code></code></code></code></code></code></code></code></code></code></code></code></code></code></code> |
时间: 2025-01-30 03:31:57