Question

我想从两个不同的表中获得几列的总和（这些表共享相同的结构）。

如果我只考虑一个表，我会写这种查询：

SELECT MONTH_REF, SUM(amount1), SUM(amount2)
    FROM T_FOO
    WHERE seller = XXX
    GROUP BY MONTH_REF;

但是，我还想使用表T_BAR中的数据，然后使用select查询返回以下列：

MONTH_REF
SUM（T_FOO.amount1）+ SUM（T_BAR.amount1）
SUM（T_FOO.amount2）+ SUM（T_BAR.amount2）

所有内容均按MONTH_REF的值分组。

请注意，给定MONTH_REF的记录可以在一个表中找到，但不能在另一个表中找到。在这种情况下，我希望获得T_FOO.amount1 + 0（或0 + T_BAR.amount1）的总和。

如何编写SQL查询以获取此信息？

有关信息，我的数据库是Oracle 10g。

Answer 1

您可以在组之前将表联合起来（顺便说一下，这是在Oracle上）：

SELECT t.month_ref, SUM(t.amount1), SUM(t.amount2)
  FROM (SELECT month_ref, amount1, amount2
          FROM T_FOO
         WHERE seller = XXX
         UNION ALL
        SELECT month_ref, amount1, amount2
          FROM T_BAR
         WHERE seller = XXX
         ) t
 GROUP BY t.month_ref

您也可以将表与卖家字段合并，稍后再过滤（如果您需要更高级的逻辑）：

 SELECT t.month_ref, SUM(t.amount1), SUM(t.amount2)
   FROM (SELECT month_ref, amount1, amount2, seller
           FROM T_FOO
          UNION ALL
         SELECT month_ref, amount1, amount2, seller
           FROM T_BAR) t
  where t.seller = XXX
  GROUP BY t.month_ref

Answer 2

您是否尝试过使用工会？

SELECT MONTH_REF, SUM(amount1), SUM(amount2)
FROM (
  SELECT MONTH_REF, SUM(amount1) AS amount1, SUM(amount2) as amount2
      FROM T_FOO
      WHERE seller = XXX
      GROUP BY MONTH_REF
  UNION ALL SELECT MONTH_REF, SUM(amount1), SUM(amount2)
      FROM T_BAR
      WHERE seller = XXX
      GROUP BY MONTH_REF
  ) tmp
GROUP BY MONTH_REF

Answer 3

或者，外部联接也应该起作用：

SELECT month_ref, 
       SUM(t_foo.amount1) + SUM(t_bar.amount1), 
       SUM(t_foo.amount2)+SUM(t_bar.amount2)
FROM   t_foo FULL OUTER JOIN t_bar
       ON t_foo.month_ref = t_bar.month_ref
GROUP BY month_ref

Answer 4

我终于使用Lieven的答案来解决这个问题了。

以下是正确的代码（amount1 = ...无法在我的环境中运行，并且查询中的;太多了：

SELECT MONTH_REF, SUM(sumAmount1), SUM(sumAmount2)
FROM (
  SELECT MONTH_REF, SUM(amount1) as sumAmount1, SUM(amount2) as sumAmount1
      FROM T_FOO
      WHERE seller = XXX
      GROUP BY MONTH_REF
  UNION ALL SELECT MONTH_REF, SUM(amount1), SUM(amount2)
      FROM T_BAR
      WHERE seller = XXX
      GROUP BY MONTH_REF
  ) tmp
GROUP BY MONTH_REF

Answer 5

SELECT (SELECT SUM(amount) from debit) as debitamounts, (SELECT SUM(amount) from credit) as creditamounts

从两个表中获取几列的总和

5 个答案: