mysql - 在 MySql 中按组计算唯一记录

Question

这是我的查询

SELECT count(*) as count 
FROM `tbl_track` 
GROUP BY `user_id`

其结果是（1人访问2次+1人访问2次+1人访问1次）

Count
2
2
1

我想要一个结果（2 人访问 2 次 + 1 人访问 1 次）

Count
2
1

Answer 1

SELECT count(*) as `count`, `visit_times` 
FROM (
  SELECT count(*) as `visit_times` 
  FROM `tbl_track` 
  GROUP BY `user_id`
) AS t GROUP BY `visit_times`

Answer 2

尝试这个：

select cnt as user_count,COUNT(*) as count
from
(
SELECT   COUNT(*) as cnt 
FROM tbl_track 
GROUP BY userid)a
group by cnt

SQL Fiddle 演示

Answer 3

尝试这个：

SELECT DISTINCT VisitsCount
FROM
(
    SELECT COUNT(*) AS VisitsCount
    FROM TableName
    GROUP BY UserId
) T