MySQL - 使用分组条件查询

Question

你好，

我的表格与上图一样，我想对所有行的数量求和，但我需要排除同一行中 AISLE = POS 且 QTY < 0 的行。

我做了一些尝试来得到我想要的，但我找不到解决方案:

SELECT
  ROUND(SUM(QTY),
  2) AS INVENTORY
FROM
  INV_QTY_LOCATION
WHERE
  PRODUCT = 143459 AND AISLE != 'PHY' AND AISLE != 'RET' AND case when AISLE = 'POS' AND QTY > 0

再试一次

SELECT
  ROUND(SUM(QTY),
  2) AS INVENTORY
FROM
  INV_QTY_LOCATION
WHERE
  PRODUCT = 143459 AND AISLE != 'PHY' AND AISLE != 'RET' AND (AISLE = 'POS' AND QTY > 0)

在此特定情况下，结果应为 161。

解决方案

SELECT
  ROUND(
    SUM(
      CASE WHEN(AISLE = 'POS' AND QTY > 0) OR AISLE != 'POS' THEN QTY ELSE 0
    END
  ),
  2
) AS INVENTORY
FROM
  INV_QTY_LOCATION
WHERE
  PRODUCT = 143459 AND AISLE != 'PHY' AND AISLE != 'RET'

Answer 1

我想指出 NOT IN 将有助于此查询:

WHERE PRODUCT = 143459 AND
      AISLE NOT IN ('PHY', 'RET') AND
      (AISLE <> 'POS' OR QTY > 0)

注意:这假设 AISLE 永远不会是 NULL。

或者，或者:

WHERE PRODUCT = 143459 AND
      AISLE NOT IN ('PHY', 'RET') AND
      NOT (AISLE = 'POS' AND QTY > 0)