表AAA有三个字段分别为:A(id) B(父id) C(内容) 默认记录如下:
1 0 A
2 0 B
3 1 C
4 3 D
5 4 E
6 0 F
7 0 G
8 5 H
...请教想实现这种列表如何写SQL...
A
C
D
E
H
...
1 0 A
2 0 B
3 1 C
4 3 D
5 4 E
6 0 F
7 0 G
8 5 H
...请教想实现这种列表如何写SQL...
A
C
D
E
H
...
from AAA a inner join (
select 父id,min(id) as mid
from AAA
group by 父id
) b on a.id=b.min
from AAA a
where not exists (select id from AAA where 父id=a.父id and id<a.id)
select a.c from tth3 a inner join ( select b,min(a) as min from tth3 group by b) b on a.a=b.min