select 数据很慢 数据一千万以上
就是一个产品表和图片表
图片表的pid是产品表的id
id name
1 c
2 b
id pid imagename
1 1 aa
2 1 bb
3 2 cc
4 2 dd
要得到结果
id name imagename
1 c aa
2 b cc
这语句在mysql还是比较快的
在pgsql就很慢
select m.*,n.imageName from (
select * from Product where userid=119 order by id desc limit 100 offset 0
) m left join ( select pid,imageName from (select id,pid,imageName from images where userid=119 ) t where t.id=(select min(id) from (select id,pid,imageName from images where userid=119 ) u where pid=t.pid) ) n on m.id=n.pid order by m.id desc
