MySQL实现差集(Minus)和交集(Intersect)

来源于   http://blog.itpub.net/29254281/viewspace-1190027/

 

MySQL实现差集(Minus)和交集(Intersect)

 

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;