Question

SQL查询语句,怎样查询重复数据

有表A, 中有字段id, name, memo
现在有很多id重复的数据,怎么把这些重复的都查出来?
group by? 请写出SQL语句, 谢谢

Answer 1

是要把重复的ID查出来嘛？
select id
from A

group by id
Having count(id)>1

Answer 2

select id, name, memo from A where id in (select id from A group by id having count(1) >= 2)