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INNER JOIN连接两个表、三个表、五个表的SQL语句

WBOY
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2016-07-11 08:44:052238검색
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SQL INNER JOIN关键字表示在表中存在至少一个匹配时,INNER JOIN 关键字返回行。

1、连接两个数据表的用法:

FROM Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort

语法格式可以概括为:

FROM 表1 INNER JOIN 表2 ON 表1.字段号=表2.字段号

2、连接三个数据表的用法:

FROM (Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort) INNER JOIN MemberLevel ON Member.MemberLevel=MemberLevel.MemberLevel

语法格式可以概括为:

FROM (表1 INNER JOIN 表2 ON 表1.字段号=表2.字段号) INNER JOIN 表3 ON 表1.字段号=表3.字段号

3、连接四个数据表的用法:

FROM ((Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort) INNER JOIN MemberLevel ON Member.MemberLevel=MemberLevel.MemberLevel) INNER JOIN MemberIdentity ON Member.MemberIdentity=MemberIdentity.MemberIdentity

语法格式可以概括为:

FROM ((表1 INNER JOIN 表2 ON 表1.字段号=表2.字段号) INNER JOIN 表3 ON 表1.字段号=表3.字段号) INNER JOIN 表4 ON Member.字段号=表4.字段号

4、连接五个数据表的用法:

FROM (((Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort) INNER JOIN MemberLevel ON Member.MemberLevel=MemberLevel.MemberLevel) INNER JOIN MemberIdentity ON Member.MemberIdentity=MemberIdentity.MemberIdentity) INNER JOIN Wedlock ON Member.Wedlock=Wedlock.Wedlock

语法格式可以概括为:

FROM (((表1 INNER JOIN 表2 ON 表1.字段号=表2.字段号) INNER JOIN 表3 ON 表1.字段号=表3.字段号) INNER JOIN 表4 ON Member.字段号=表4.字段号) INNER JOIN 表5 ON Member.字段号=表5.字段号
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