MySQL实现差集(Minus)和交集(Intersect)

tianxia71527 8年前

MySQL没有实现Minus和Intersect功能，就像它也没有实现cube的功能一样。

可以用SQL实现同样的功能,就是麻烦了点。

drop table t1;

drop table t2;

create table t1(id int primary key,nickname varchar(20),playNum varchar(20));

create table t2(id int primary key,nickname varchar(20),playNum varchar(20));

insert into t1 values(1,1,10);

insert into t1 values(2,2,20);

insert into t1 values(3,3,30);

insert into t2 values(1,1,10);

insert into t2 values(2,2,200);

insert into t2 values(3,33,300);

commit;

MySQL实现交集

SELECT id, nickname, playNum, COUNT(*)

FROM (SELECT id, nickname, playNum

FROM t1

UNION ALL

SELECT id, nickname, playNum

FROM t2

) a

GROUP BY id, nickname, playNum

HAVING COUNT(*) > 1

MySQL实现差集

SELECT t1.id, t1.nickname, t1.playNum

FROM t1 LEFT JOIN t2 ON t1.id = t2.id

WHERE t1.nickname != t2.nickname

OR t1.playNum != t2.playNum;

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