奇怪这条sql为什么不能出现结果select familyName,givenName,addressLine1 from User m where (m.familyName, m.givenName) in
(select b.familyName,b.givenName from User b
where
trim(ifnull(b.familyName,'')) <>'' and trim(ifnull(b.givenName,'')) <>''
group by b.familyName,b.givenName having count(*)>=2) union
select familyName,givenName,addressLine1 from User m where m.addressLine1 in
(select b.addressLine1 from User b
where trim(ifnull(b.addressLine1,'')) <>''
group by b.addressLine1 having count(*)>=2) 单独2个sql(union前后)是可以的,
但放在一起为什么不可以? 死活没有结果
(select b.familyName,b.givenName from User b
where
trim(ifnull(b.familyName,'')) <>'' and trim(ifnull(b.givenName,'')) <>''
group by b.familyName,b.givenName having count(*)>=2) union
select familyName,givenName,addressLine1 from User m where m.addressLine1 in
(select b.addressLine1 from User b
where trim(ifnull(b.addressLine1,'')) <>''
group by b.addressLine1 having count(*)>=2) 单独2个sql(union前后)是可以的,
但放在一起为什么不可以? 死活没有结果
解决方案 »
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mysql> select * from t1;
+---+------+
| a | b |
+---+------+
| 1 | A |
| 2 | B |
| 3 | C |
+---+------+
3 rows in set (0.00 sec)mysql> select * from tb;
+----+-------+
| id | name |
+----+-------+
| 1 | wang' |
+----+-------+
1 row in set (0.00 sec)mysql> select * from t1
-> union
-> select * from tb;
+---+-------+
| a | b |
+---+-------+
| 1 | A |
| 2 | B |
| 3 | C |
| 1 | wang' |
+---+-------+
4 rows in set (0.00 sec)
就是不能union ,否则漫长等待, 15分钟 半小时过去
还是不出结果这个user也不过3万的记录