SQL各Join的结果区别

2014-11-24 01:39:33 · 作者: · 浏览: 5

假设有部门表(DeptTB):

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用户表(UserTB):

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1、Join (Inner Join)

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如:< http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vc3Ryb25nPjwvcD4KPHA+PC9wPgo8cHJlIGNsYXNzPQ=="brush:sql;">SELECT * FROM dbo.UserTB JOIN dbo.DeptTB ON dbo.UserTB.deptId=dbo.DeptTB.deptId结果:

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2、Left Join

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如:

SELECT * FROM dbo.UserTB LEFT JOIN dbo.DeptTB ON dbo.UserTB.deptId=dbo.DeptTB.deptId
结果:

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3、Right Join

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如:

SELECT * FROM dbo.UserTB RIGHT JOIN dbo.DeptTB ON dbo.UserTB.deptId=dbo.DeptTB.deptId

结果:

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4、Full Join

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如:

SELECT * FROM dbo.UserTB FULL JOIN dbo.DeptTB ON dbo.UserTB.deptId=dbo.DeptTB.deptId

结果: