Question

表名：A 字段： ID1 ID2 要求：当ID1有重复时删除ID2的值较小的一行数据 求SQL语句

Answer 1

delete A t
where ( select count(*) from A where ID1 = t.ID1 ) > 1
and ID2 = ( select min(ID2) from A where ID1= t.ID1 )

Answer 2

DELETE A
WHERE
EXISTS (
SELECT 1
FROM A SubA
WHERE A.id1 = SubA.id1 AND A.id2 < SubA.id2
)

Answer 3

环境慢化剂搞活