尽量不要用not in 或in语句,我画了一下文氏图,整理为如下语句:
(SELECT A,B FROM T1
union
SELECT A,B FROM T2
union
SELECT A,B FROM T3)
intersect
(select T1.A,T1.B from T1,T2 WHERE T1.A=T2.A AND T1.B=T2.B)
(SELECT A,B FROM T1
union
SELECT A,B FROM T2
union
SELECT A,B FROM T3)
intersect
(select T1.A,T1.B from T1,T2 WHERE T1.A=T2.A AND T1.B=T2.B)
解决方案 »
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