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今天看mysql视频,里边老师给总结了一下七种join语句,感觉挺好的。分享一下
select * from TableA a inner join TableB b on a.id =b.aid
select * from TableA a left join TableB b on a.id =b.aid
select * from TableA a right join TableB b on a.id =b.aid
select * from TableA a left join TableB b where b.aid is null
selet * from TableA a right join TableB b on a.id =b.aid where a.id is null
select * from TableA a left join TableB b on a.id =b.aid
union
select * from TableA a right join TableB b on a.id =b.aid
select * from TableA a left join TableB b where b.aid is null
union
select * from TableA a right join TableB b where a.id is null