Question

mysql count()用法？

id uid time
1 2 20130327

2 1 20130326

3 2 20130325

4 3 20130324

5 2 20130323
要求本周活跃用户数，即有3次登录就算是活跃用户了

SELECT COUNT(*) FROM table名 GROUP BY uid
这样可以算出每一个用户登录的次数
请问能不能用sql语句算出count(*)>3时的个数

Answer 1

select count(*) from (SELECT COUNT(*) as cnt FROM table名 GROUP BY uid ) a where a.cnt > 3

Answer 2

SELECT
count( 1 )
FROM
(
SELECT uid FROM 表 GROUP BY uid having COUNT(*) > 3
) subquery

Answer 3

select * from t_table where count(*) >3 group by uid;

Answer 4

SELECT COUNT(*) FROM table名 GROUP BY uid having count(*)>3