Question

我想要这个表的结果集：

ID  Number_of_posts   Number_of_user
1   100               21
2   23                34

as

   ID  Number_of_posts   Number_of_user   Number_of_posts_AND_Number_of_user
    1   100               21               178
    2   23                34               178
-----------------------------------------------
        123                55

是否有可能将两个列的总和作为另一列/作为mysql中的输出？

Answer 1

获取交叉表总计（水平和垂直）：

select id,
       number_of_posts as p,
       number_of_users as u,
       number_of_posts+number_of_users as p_and_u
    from tbl
union all
select 99999 as id,
       sum(number_of_posts) as p,
       sum(number_of_users) as u,
       sum(number_of_posts+number_of_users) as p_and_u
    from tbl
order by 1

这会给你：

   id     p     u   p_and_u
-----   ---   ---   -------
    1   100    21       121
    2    23    34        57
99999   123    55       178

Answer 2

您不必要地使查询复杂化并使用更多内存。在一个查询中拉出记录，然后进行另一个查询以获取聚合。

我知道它没有回答你的问题，但这是你应该做的事情。 =）

Answer 3

SELECT  id, number_of_posts, number_of_user,
        (
        SELECT  SUM(number_of_posts + number_of_user)
        FROM    mytable
        )
FROM    mytable

Answer 4

SELECT SUM(Number_of_posts), SUM(Number_of_user) FROM table;

Answer 5

SELECT *, 
       (SELECT SUM(Number_of_posts) + SUM(Number_of_user) FROM TABLE) AS total 
FROM table;

（编辑：最初没有注意到它是最后一栏中的总数。）

Answer 6

MySQL是否支持ROLLUP？

SELECT id,
       SUM(Number_of_posts) Number_of_posts,
       SUM(Number_of_user) Number_of_user,
       SUM(Number_of_posts) + SUM(Number_of_user) Number_of_posts_AND_Number_of_user
  FROM table
  GROUP BY ROLLUP(id)

编辑：基于快速搜索，在MySQL中最后一行可能是GROUP BY id WITH ROLLUP。

在mysql中总计两列

6 个答案: