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废话不多说了,直接给大家贴代码了,具体代码如下所示:
-- 交叉连接产生笛卡尔值 (X*Y) SELECT * FROM Student cross Join dbo.ClassInfo --另外一种写法 SELECT * FROM Student , ClassInfo -- 内连接 (Inner 可以省略) SELECT * FROM Student JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID; -- Inner Join SELECT * FROM Student INNER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID; -- on 条件,通常是 主外键,但是不限于主外键 -- on 条件,允许有多个,而且可能是针对某个表的 SELECT * FROM Student INNER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID AND dbo.Student.Class IN (1,2) -- 针对Student表增加查询条件 -- 不等于 (笛卡尔值减去 相等的值) SELECT * FROM Student INNER JOIN dbo.ClassInfo ON dbo.Student.Class <> dbo.ClassInfo.ID; --自连接 从Class表中查询到Class所在的系 SELECT T1.* ,T2.ClassName FROM dbo.ClassInfo AS T1 INNER JOIN dbo.ClassInfo AS T2 ON T1.PID=T2.ID -- Left Join SELECT * FROM Student Left JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID; -- Right Join SELECT * FROM Student RIGHT JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID; -- 全外连接 SELECT * FROM Student FULL OUTER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID; -- 外连接和内连接的区别是: -- 内连接,on条件不符合的话,会过滤掉数据 -- 外连接,以保留表为主,on条件成立显示数据,否则显示NULL --Union 纵向连接 SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM Student WHERE StuID<=2 UNION SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM dbo.Student WHERE StuID>2 --Union 去重复 SELECT StuSex FROM Student WHERE StuID<=2 UNION SELECT StuSex FROM dbo.Student WHERE StuID>2 --Union 显示全部 SELECT StuSex FROM Student WHERE StuID<=2 UNION ALL SELECT StuSex FROM dbo.Student WHERE StuID>2 --Except 差集,排除 SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM Student Except SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM dbo.Student WHERE StuID<=2 --Intersect 交集 SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM Student WHERE StuID>=2 Except SELECT StuID,StuName,StuEnName,StuAge,StuBirthday FROM dbo.Student WHERE StuID<=3
以上所述是小编给大家介绍的SQL Server 2012 多表连接查询功能实例代码,希望对大家有所帮助,如果大家有任何疑问欢迎给我留言,小编会及时回复大家的!
到此这篇关于SQLServer2012多表连接查询功能实例代码就介绍到这了。正在奋斗路上的你,千万不要怕吃苦。没有什么捷径能让你出类拔萃,没有哪些艰难困苦是白白煎熬。你的每一份经历,不管是顺境还是坎坷,都会增加你生命的厚度。所有的苦,以后都会笑着说出来。更多相关SQLServer2012多表连接查询功能实例代码内容请查看相关栏目,小编编辑不易,再次感谢大家的支持!