举个例子,比如数据库中有如下数据 a1 a2 code a3 a4 1 a aaa a a 2 b bbb b b 3 c aaa c c 4 d bbb d d 5 e eee e e 6 f ddd f f 7 g bbb g g 8 h eee h h 9 i eee i i 10 j aaa j j 如何用一条语句取得这样记录集,去掉code中重复的字段,取a1是最小的,如下 a1 a2 code a3 a4 1 a aaa a a 2 b bbb b b 5 e eee e e 6 f ddd f f
select min(a1), code from table group by code 肯定没问题 我试过
SELECT * FROM table1 WHERE a1 in (SELECT min(a1) FROM table1 GROUP BY code);
a1 a2 code a3 a4
1 a aaa a a
2 b bbb b b
3 c aaa c c
4 d bbb d d
5 e eee e e
6 f ddd f f
7 g bbb g g
8 h eee h h
9 i eee i i
10 j aaa j j
如何用一条语句取得这样记录集,去掉code中重复的字段,取a1是最小的,如下
a1 a2 code a3 a4
1 a aaa a a
2 b bbb b b
5 e eee e e
6 f ddd f f
FROM table1
WHERE a1 in
(SELECT min(a1)
FROM table1
GROUP BY code);