SQL INNER JOIN關(guān)鍵字表示在表中存在至少一個(gè)匹配時(shí),INNER JOIN 關(guān)鍵字返回行。
1、連接兩個(gè)數(shù)據(jù)表的用法:
FROM Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort
語(yǔ)法格式可以概括為:
FROM 表1 INNER JOIN 表2 ON 表1.字段號(hào)=表2.字段號(hào)
2、連接三個(gè)數(shù)據(jù)表的用法:
FROM (Member INNER JOIN MemberSort ON Member.MemberSort=MemberSort.MemberSort) INNER JOIN MemberLevel ON Member.MemberLevel=MemberLevel.MemberLevel
語(yǔ)法格式可以概括為:
FROM (表1 INNER JOIN 表2 ON 表1.字段號(hào)=表2.字段號(hào)) INNER JOIN 表3 ON 表1.字段號(hào)=表3.字段號(hào)
3、連接四個(gè)數(shù)據(jù)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
語(yǔ)法格式可以概括為:
FROM ((表1 INNER JOIN 表2 ON 表1.字段號(hào)=表2.字段號(hào)) INNER JOIN 表3 ON 表1.字段號(hào)=表3.字段號(hào)) INNER JOIN 表4 ON Member.字段號(hào)=表4.字段號(hào)
4、連接五個(gè)數(shù)據(jù)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
語(yǔ)法格式可以概括為:
FROM (((表1 INNER JOIN 表2 ON 表1.字段號(hào)=表2.字段號(hào)) INNER JOIN 表3 ON 表1.字段號(hào)=表3.字段號(hào)) INNER JOIN 表4 ON Member.字段號(hào)=表4.字段號(hào)) INNER JOIN 表5 ON Member.字段號(hào)=表5.字段號(hào)