如何获得子查询中不同项目的总和？答案

【问题标题】：How can I get the sum of distinct items in a subquery?如何获得子查询中不同项目的总和？
【发布时间】：2019-12-11 22:03:24
【问题描述】：

这是我目前的查询。

SELECT DISTINCT(ITEM_NAME),
  DESCRIPTION,
  SUM(wm_inventory.ON_HAND_QTY) "INV",
  (SELECT DISTINCT(ITEM_NAME),
    SUM(wm_inventory.ON_HAND_QTY)
    FROM LOCN_HDR lh
    INNER JOIN wm_inventory
    ON lh.LOCN_ID = wm_inventory.LOCATION_ID
    INNER JOIN item_cbo
    ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
    where zone = 'BK5') as "QTY"
FROM LOCN_HDR lh
INNER JOIN wm_inventory
ON lh.LOCN_ID = wm_inventory.LOCATION_ID
INNER JOIN item_cbo
ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
WHERE ZONE IN ('BK1','BK2','BK3','BK4')
and ITEM_NAME in (SELECT DISTINCT(item_cbo.ITEM_NAME)
    FROM LOCN_HDR lh
    INNER JOIN wm_inventory
    ON lh.LOCN_ID = wm_inventory.LOCATION_ID
    INNER JOIN item_cbo
    ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
    where zone = 'BK5')
GROUP BY ITEM_NAME,
DESCRIPTION
ORDER BY ITEM_NAME

在此之后，我收到错误“ORA-00913：值太多”，因为 select 语句中的子查询正在拉两列。有解决办法吗？

基本上我需要提取两组不同位置的库存并并排比较。

我需要另一列包含“BK5”位置的库存。 “数量”列当前包含 BK1-4 位置的总和。

【问题讨论】：

提供一些样本数据集和预期输出。
添加的图片是查询成功的图片，子查询中没有（SELECT DISTINCT(ITEM_NAME)）
你知道DISTINCT 适用于一行，而不是一列？您对DISTINCT(x) 的使用可能没有达到您的预期。
它正在做我在这种情况下需要它做的事情。它正确评估库存
如果您这么说，但您不需要在选择中使用 DISTINCT - GROUP BY 会为您处理。无论如何，我认为您的要求只是进行相关的子查询。所以你需要一个别名。我会写一个答案！

标签： sql oracle

【解决方案1】：

您可以将子查询移动到 CTE 表达式 With temp_table_name as (subquery..) 或使用窗口函数 sum(column1)over( partition by column2 order by xxxx)

我想第一种方法可能类似于以下内容，（我目前无法访问 SQL 编辑器，因此您可能需要注意语法或琐碎错误）

    With qty_src as (
    SELECT ITEM_NAME ,
    SUM(wm_inventory.ON_HAND_QTY)  as qty
    FROM LOCN_HDR lh
    INNER JOIN wm_inventory
    ON lh.LOCN_ID = wm_inventory.LOCATION_ID
    INNER JOIN item_cbo
    ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
    where zone = 'BK5'
)
SELECT DISTINCT(ITEM_NAME),
  DESCRIPTION,
  SUM(wm_inventory.ON_HAND_QTY) "INV",
  qty_src.qty as "QTY"
FROM LOCN_HDR lh
INNER JOIN wm_inventory
ON lh.LOCN_ID = wm_inventory.LOCATION_ID
INNER JOIN item_cbo
ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
LEFT JOIN qty_src
    on qty_src.ITEM_NAME = lh.ITEM_NAME
WHERE ZONE IN ('BK1','BK2','BK3','BK4')
and ITEM_NAME in (SELECT DISTINCT(item_cbo.ITEM_NAME)
    FROM LOCN_HDR lh
    INNER JOIN wm_inventory
    ON lh.LOCN_ID = wm_inventory.LOCATION_ID
    INNER JOIN item_cbo
    ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
    where zone = 'BK5')
GROUP BY ITEM_NAME,
DESCRIPTION
ORDER BY ITEM_NAME

With 语句在上面声明了某种形式的临时表（公用表表达式），我们将其命名为 qty_src，然后将其左连接到主查询中以获取总和值。

我从子查询中删除了 distinct 语句，因为聚合函数 sum()....group by 会明确过滤字段。

【讨论】：

【解决方案2】：

    SELECT ITEM_NAME,
      DESCRIPTION,
      SUM(wm_inventory.ON_HAND_QTY) "INV",
      (SELECT 
        SUM(wm_inventory.ON_HAND_QTY)
        FROM LOCN_HDR lh
        INNER JOIN wm_inventory
        ON lh.LOCN_ID = wm_inventory.LOCATION_ID
        INNER JOIN item_cbo_sub_query
        ON wm_inventory.ITEM_ID = item_cbo_sub_query.ITEM_ID
        where zone = 'BK5'
        AND item_cbo_sub_query.ITEM_ID=item_cbo.ITEM_ID
) as "QTY BK5"
    FROM LOCN_HDR lh
    INNER JOIN wm_inventory
    ON lh.LOCN_ID = wm_inventory.LOCATION_ID
    INNER JOIN item_cbo
    ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
    WHERE ZONE IN ('BK1','BK2','BK3','BK4')
    and ITEM_NAME in (SELECT item_cbo.ITEM_NAME
        FROM LOCN_HDR lh
        INNER JOIN wm_inventory
        ON lh.LOCN_ID = wm_inventory.LOCATION_ID
        INNER JOIN item_cbo
        ON wm_inventory.ITEM_ID = item_cbo.ITEM_ID
        where zone = 'BK5')
    GROUP BY ITEM_NAME,
    DESCRIPTION
    ORDER BY ITEM_NAME

【讨论】：