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Home Backend Development PHP Tutorial 帮忙写条简单的sql

帮忙写条简单的sql

Jun 23, 2016 pm 01:52 PM
sql Simple



a表 b表 c表  ,a表和b表条件关联gid ,b表和c表关联cid,我要怎么把这3个表联表呀?
条件是gid=20


数据库类型:mysql


回复讨论(解决方案)

select * from b left join(a,c) on (a.gid=b.gid and c.cid=b.cid) where b.gid=20
Copy after login

如果不想要可能出现的 NULL,则
select * from a,b,c where a.gid=b.gid and b.cid=c.cid and a,gid=20
Copy after login

你安装一个Navicat,建立一个视图,完全不需要手写了。 直接拖就行。 

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