Question

我有以下两个表：

STOCK_ON_HAND：这显示了我手头上的所有库存 STOCK_ON_ORDER：这向我显示了我所订购的所有库存

我有以下两个查询来汇总表：

SELECT STOCK_CODE, SUM(QTY)
FROM STOCK_ON_HAND
GROUP BY STOCK_CODE
HAVING SUM(QTY) <>0;

和

SELECT STOCK_CODE, SUM(ON_ORDER)
FROM STOCK_ON_ORDER
GROUP BY STOCK_CODE
HAVING SUM(STOCK_ON_ORDER) <>0;

我基本上想将上述内容与一个表合并显示以下字段：

STOCK_CODE
STOCK_ON_HAND
STOCK_ON_ORDER

实现此目标的最佳方法是什么？

Answer 1

为此，您需要一个FULL OUTER JOIN，Access不直接支持它，但是您可以使用UNION模拟它，如下所示：

SELECT h.STOCK_CODE, h.HQTY AS STOCK_ON_HAND, o.OQTY AS STOCK_ON_ORDER
FROM (
  SELECT STOCK_CODE, SUM(QTY) AS HQTY
  FROM STOCK_ON_HAND
  GROUP BY STOCK_CODE
  HAVING SUM(QTY) <> 0
) h LEFT JOIN (
  SELECT STOCK_CODE, SUM(ON_ORDER) AS OQTY
  FROM STOCK_ON_ORDER
  GROUP BY STOCK_CODE
  HAVING SUM(ON_ORDER) <> 0
) o ON o.STOCK_CODE = h.STOCK_CODE
UNION
SELECT o.STOCK_CODE, h.HQTY AS STOCK_ON_HAND, o.OQTY AS STOCK_ON_ORDER
FROM (
  SELECT STOCK_CODE, SUM(QTY) AS HQTY
  FROM STOCK_ON_HAND
  GROUP BY STOCK_CODE
  HAVING SUM(QTY) <> 0
) h RIGHT JOIN (
  SELECT STOCK_CODE, SUM(ON_ORDER) AS OQTY
  FROM STOCK_ON_ORDER
  GROUP BY STOCK_CODE
  HAVING SUM(ON_ORDER) <> 0
) o ON o.STOCK_CODE = h.STOCK_CODE

如果您不想在结果中看到null（如果存在），而是将它们替换为0，请使用函数Nz()，如下所示：

SELECT h.STOCK_CODE, Nz(h.HQTY, 0) AS STOCK_ON_HAND, Nz(o.HQTY, 0) AS STOCK_ON_ORDER

或从两个表中获取不同的STOCK_CODE，然后LEFT JOIN到每个表中：

SELECT c.STOCK_CODE, h.HQTY AS STOCK_ON_HAND, o.OQTY AS STOCK_ON_ORDER
FROM ((
  SELECT STOCK_CODE FROM STOCK_ON_HAND
  UNION
  SELECT STOCK_CODE FROM STOCK_ON_ORDER
) AS c LEFT JOIN (
  SELECT STOCK_CODE, SUM(QTY) AS HQTY
  FROM STOCK_ON_HAND
  GROUP BY STOCK_CODE
  HAVING SUM(QTY) <> 0
) h ON h.STOCK_CODE = c.STOCK_CODE )
LEFT JOIN (
  SELECT STOCK_CODE, SUM(ON_ORDER) AS OQTY
  FROM STOCK_ON_ORDER
  GROUP BY STOCK_CODE
  HAVING SUM(ON_ORDER) <> 0
) o ON o.STOCK_CODE = c.STOCK_CODE

Answer 2

我建议在汇总之前先做UNION ALL：

SELECT STOCK_CODE, SUM(on_hand), SUM(on_order)
FROM (SELECT STOCK_CODE, SUM(QTY) as on_hand, 0 on_order
      FROM STOCK_ON_HAND
      GROUP BY STOCK_CODE
      UNION ALL
      SELECT STOCK_CODE, 0, SUM(ON_ORDER) as on_order
      FROM STOCK_ON_ORDER
      GROUP BY STOCK_CODE
     ) s
GROUP BY STOCK_CODE
HAVING on_hand <> 0 OR on_order <> 0;

如果MS Access在UNION ALL子句中不支持FROM，则可以使用视图进行设置。

将两个选择查询的结果合并到一个表中

2 个答案: