mysql - MySQL 中所有行的计数总和 (*)

Question

我被 sum() 查询困住了，我想要所有行中 count(*) 值的总和 group by .

这里是查询:

select
    u.user_type as user,
    u.count,
    sum(u.count)
FROM
(
select 
    DISTINCT
    user_type,
    count(*) as count
FROM
    users
where
    (user_type = "driver" OR user_type = "passenger")
GROUP BY
    user_type
) u;

当前输出:

----------------------------------
|  user     |  count     |  sum  |
----------------------------------
| driver    | 58         |  90   |
----------------------------------

预期输出:

----------------------------------
|  user     |  count     |  sum  |
----------------------------------
| driver    | 58         |  90   |
| passenger | 32         |  90   |
----------------------------------

如果我从查询中删除 sum(u.count)，则输出如下所示:

--------------------------
|  user     |  count     |
--------------------------
| driver    | 58         |
| passenger | 32         |
--------------------------

Answer 1

你需要一个子查询:

   SELECT user_type, 
          Count(*) AS count,
          (SELECT COUNT(*) 
           FROM users 
           WHERE user_type IN ("driver","passenger" )) as sum  
   FROM   users 
   WHERE  user_type IN ("driver","passenger" ) 
   GROUP  BY user_type ; 

注意这里不需要distinct。

或

   SELECT user_type, 
          Count(*) AS count,
          c.sum
   FROM   users 
   CROSS JOIN ( 
           SELECT COUNT(*) as sum
           FROM users 
           WHERE user_type IN ("driver","passenger" )
         ) as c

   WHERE  user_type IN ("driver","passenger" ) 
   GROUP  BY user_type ;