Question

给出SQL：是否可以引入结果集的总数？

SELECT 
    SUM(CASE
        WHEN status = 3 THEN 1
        ELSE 0
    END) AS Open,
    SUM(CASE
        WHEN status = 4 THEN 1
        ELSE 0
    END) AS Close
FROM
    Table1
WHERE
    id = 2;

结果：

Open,Close
5,5

所需结果：

Open,Close,Total
5,5,10

Answer 1

只需添加另一个案例声明

SELECT 
    SUM(CASE
        WHEN status = 3 THEN 1
        ELSE 0
    END) AS Open,
    SUM(CASE
        WHEN status = 4 THEN 1
        ELSE 0
    END) AS Close
    SUM(CASE
        WHEN status IN (3, 4) THEN 1
        ELSE 0
    END) AS Total
FROM
    Table1
WHERE
    id = 2;

Answer 2

您可以使用CTE：

WITH sumCase AS (
SELECT 
    SUM(CASE
        WHEN status = 3 THEN 1
        ELSE 0
    END) AS Open,
    SUM(CASE
        WHEN status = 4 THEN 1
        ELSE 0
    END) AS Close
FROM
    Table1
WHERE
    id = 2;)
SELECT Open,Close, Open + Close AS Total FROM Table1;

http://www.mysqltutorial.org/mysql-cte/

Answer 3

使用子查询

   select open,close,open+close as total from
    (
       SELECT 
        SUM(CASE  WHEN status = 3 THEN 1
             ELSE 0
             END ) AS Open,
       SUM(CASE   WHEN status = 4 THEN 1
           ELSE 0
           END) AS Close
    FROM
    Table1
    WHERE   id = 2   ) as T

有没有办法包括所有案例的总和？

3 个答案: