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MYSQL多表联合查询的问题

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Release： 2016-06-06 20:45:28
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总共有三个表

post表：id,title,content
terms表：id,name
rela表：postid,termid

post表保存文章内容（文章ID、文章标题、文章内容），terms表保存分类内容（分类ID、分类名称），rela表保存的是文章分类信息，也就是文章ID对应的分类ID。

单纯匹配post表的title和content我知道是这样

<code>query( 
        "
        SELECT id, title
        FROM post
        WHERE (
            `title` LIKE  '%关键词%'
            OR  `content` LIKE  '%关键词%'
        )
        LIMIT 0 , 30
        "
    );
</code>
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现在也要匹配相应的terms表的name，请问怎么写呢？

回复内容：

总共有三个表

post表：id,title,content
terms表：id,name
rela表：postid,termid

post表保存文章内容（文章ID、文章标题、文章内容），terms表保存分类内容（分类ID、分类名称），rela表保存的是文章分类信息，也就是文章ID对应的分类ID。

单纯匹配post表的title和content我知道是这样

<code>query( 
        "
        SELECT id, title
        FROM post
        WHERE (
            `title` LIKE  '%关键词%'
            OR  `content` LIKE  '%关键词%'
        )
        LIMIT 0 , 30
        "
    );
</code>
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Copy after login

现在也要匹配相应的terms表的name，请问怎么写呢？

<code>select post.id, post.title from rela left join post on rela.postid = post.id left join terms on rela.termid = terms.id where post.title like '%关键词%' or post.content like '%关键词%' or terms.name like '%关键词%'
</code>
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联合查询是 Mysql 比较基础的操作，题主应该花点时间掌握这个基础知识点。:)

Related labels：
mysql php
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