mysql - 如何在mysql中添加两个求和值

Question

是否可以像下面显示的查询(图 1)那样在 mysql 中添加两个求和值？

我有下面的查询，我正在尝试添加数量和专业。

图一

    SELECT  

    SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) AS qty,
    SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END) AS pro

    SUM(pro + qty)

    FROM OrderDetails;

我将需要在整个查询过程中多次使用 qty 和 pro，所以我不想编写如图 2 所示的查询

图 2

    SELECT  

    SUM(
    SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END)
    + 
    SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END)
    )

    FROM OrderDetails;

已编辑

我在整个查询过程中多次使用 qty 和 pro 的意思如下。

查询示例一 - 是我正在尝试做的，我可以在整个查询过程中多次重复使用 qty 和 pro，比如 sum(pro + qty) 和 having (qty > 0 AND pro > 0)，而无需重写整个求和语句。

SELECT  

SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) AS qty,
SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END) AS pro

SUM((pro + qty)/100)

FROM OrderDetails

GROUP BY value

HAVING (
       qty > 2
       AND
       pro > 2
       )
;

查询示例 2 - 是我目前必须做的，而且必须重写 SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 似乎是非常糟糕的做法0 END) 多次，而不是像上面的查询中那样简单的 qty 或 pro

SELECT  

SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) AS qty,
SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END) AS pro

SUM((
     SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END)
      +
     SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END)
)/100)

FROM OrderDetails

GROUP BY value

HAVING (
       SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) > 2
       AND
       SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END) > 2
       )
;

在 SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) AS 这样的示例中定义一次后是否无法添加 SUM(pro + qty)数量

Answer 1

您可以使用以下查询进行计算。

SELECT  

SUM(CASE WHEN value > 0 AND xp = 0 THEN 1 ELSE 0 END) AS qty,
SUM(CASE WHEN value > 1 AND xp = 2 THEN 1 ELSE 0 END) AS pro,
SUM(CASE 
        WHEN value > 0 AND xp = 0 THEN 1
        WHEN value > 1 AND xp = 2 THEN 1 
    ELSE 0 END) AS qtyProSum
FROM OrderDetails;