如何在分组查询中添加“总计”行(在Postgresql中)?

时间:2015-01-07 18:33:32

标签: sql postgresql group-by

如何在SELECT的末尾添加一行,以便查看分组行的总数? (我需要'钱'和'请求'的总额:

SELECT 
    organizations.name || ' - ' || section.name as Section, 
    SUM(requests.money) as money, 
    COUNT(*) as requests
FROM 
    schema.organizations
   -- INNER JOINs omitted --
WHERE 
    -- omitted --
GROUP BY 
    -- omitted --
ORDER BY 
    -- omitted --

运行以上产生:

|*Section*  | *Money* | *Requests*|
|-----------|---------|-----------|
|BMO - HR   |564      |10         |
|BMO - ITB  |14707    |407        |
|BMO - test |15       |7          |

现在我想要的是在显示的内容的末尾添加一个总数:

|BMO - Total|15286    |424        |

我尝试了一些事情,最后尝试将select包装在WITH语句中并失败:

WITH w as (
    --SELECT statement from above--
)
SELECT * FROM w UNION ALL 
   SELECT 'Total', money, requests from w

这会产生奇怪的结果(我总共得到四行 - 当时应该只有一行。

非常感谢任何帮助!

由于

2 个答案:

答案 0 :(得分:2)

您可以使用UNION查询来实现此目的。在下面的查询中,我添加了一个人工排序列并将联合查询包装在外部查询中,以便总和出现在底部。

[我假设您将按条款添加联接和分组...]

SELECT section, money, requests FROM  -- outer select, to get the sorting right.

(    SELECT 
        organizations.name || ' - ' || section.name as Section, 
        SUM(requests.money) as money, 
        COUNT(*) as requests,
        0 AS sortorder -- added a sortorder column
     FROM 
        schema.organizations
    INNER JOINs omitted --
    WHERE 
        -- omitted --
    GROUP BY 
        -- omitted --
       --  ORDER BY is not used here


UNION

    SELECT
       'BMO - Total' as section,
        SUM(requests.money) as money, 
        COUNT(*) as requests,
        1 AS sortorder
    FROM 
        schema.organizations
        -- add inner joins and where clauses as before
) AS unionquery

ORDER BY sortorder -- could also add other columns to sort here

答案 1 :(得分:0)

https://stackoverflow.com/a/54913166/1666637答案中的汇总功能可能是执行此操作的便捷方法。有关此功能和相关功能的更多信息,请点击此处:https://www.postgresql.org/docs/devel/queries-table-expressions.html#QUERIES-GROUPING-SETS

类似这样的未经测试的代码

WITH w as (
    --SELECT statement from above--
)
SELECT * FROM w ROLLUP((money,requests))

请注意双括号,它们是有效的