Question

我构建了三个SQL查询，它们对一组约八个表进行操作。三个中的每一个在其group by子句中具有相同的参数。我正在尝试合并这三个查询，以生成单个输出表，虽然我尝试的所有内容似乎都打破了工作基础查询。

我想要一个看起来像的输出

[heading] [query1 output column] [query2 output column] [query3 output column]

，[heading]列是三个现有查询的group by子句中使用的现有参数。

我意识到我在这里展示了我的新意，虽然我被卡住了，并且在同一个错误的圈子里走了太多次......

编辑 *

我认为代码片段会让人感到困惑，尽管这是一个略微缩写的版本;

SELECT 
TITLE_COUNT.index, 
COUNT  (TITLE_COUNT.TTOTAL) AS TITLES,
COUNT (AUTHOR_COUNT.TTOTAL) AS AUTHOR
FROM(
    SELECT 
    index, title, date,
    COUNT (*) AS TTOTAL
    FROM (SELECT DISTINCT index, title, date FROM TableP P) P
    GROUP BY
    index, title, date
    ORDER BY
    index
) AS TITLE_COUNT,
(
    SELECT 
    index, 
    COUNT (*) AS TTOTAL
    FROM (SELECT DISTINCT index, FROM TableM M) M
    GROUP BY
    index
    ORDER BY
    index
) AS AUTHOR_COUNT
WHERE
TITLE_COUNT.index = AUTHOR_COUNT.index
GROUP BY
TITLE_COUNT.index
;

我的问题是，输出表中的计数列已成倍增加。例如，站在查询中给我一些类似

的内容

TITLE
index count
001     12
002     10
003     15

AUTHOR
index  count
001    2
002    4
003    6

虽然上面的查询结果是

001    24
002    40
003    90

Answer 1

不要重复计算：

SELECT 
TITLE_COUNT.index, 
TITLE_COUNT.TTOTAL AS TITLES,
AUTHOR_COUNT.TTOTAL AS AUTHOR
FROM(
    SELECT 
    index, title, date,
    COUNT (*) AS TTOTAL
    FROM (SELECT DISTINCT index, title, date FROM TableP P) P
    GROUP BY
    index, title, date
    ORDER BY
    index
) AS TITLE_COUNT
FULL OUTER JOIN (
    SELECT 
    index, 
    COUNT (*) AS TTOTAL
    FROM (SELECT DISTINCT index, FROM TableM M) M
    GROUP BY
    index
    ORDER BY
    index
) AS AUTHOR_COUNT
   ON TITLE_COUNT.index = AUTHOR_COUNT.index
GROUP BY
    TITLE_COUNT.index

通过参数将查询与公共组合并

1 个答案: