Question

sql seever怎么查出某个字段重复出现两次以上的数据

Answer 1

SELECT 字段 FROM 表 GROUP BY 字段 HAVING COUNT(字段) > 1

SELECT * FROM 表 WHERE 字段 IN(SELECT 字段 FROM 表 GROUP BY 字段 HAVING COUNT(字段) > 1)

Answer 2

select c1 from t1 group by c1 having count(c1)>=2

Answer 3

select * from 表 where 字段 in( select 字段 from 表 ...

Answer 4

count函数