SQLite 显示 SUM 占总 SUM 的百分比

Question

我有一个 table 需要一些费用。我想select类别（不重复），每个类别的费用总和，以及这笔费用占总费用的百分比。

前两件事我成功了，但总的来说我没有。我想是因为 GROUP BY.

SELECT SUM(Value), [Expense Category]
FROM expenses
WHERE Year = 2021
GROUP BY [Expense Category]
ORDER BY SUM(Value) DESC

我可以在这个 SELECT 中包含总金额吗？怎么样？

谢谢！

Answer 1

在这种情况下，您可以使用 window 函数

SELECT DISTINCT SUM(Value) over(partition by [Expense Category])/SUM(Value), [Expense Category]
FROM expenses
WHERE Year = 2021
GROUP BY [Expense Category]

或者在子查询中计算总和

SELECT [Expense Category], sum_/total_sum
(
    SELECT SUM(Value) sum_, [Expense Category]
    FROM expenses
    WHERE Year = 2021
    GROUP BY [Expense Category]
    ORDER BY SUM(Value) DESC
) a 
CROSS JOIN (SELECT SUM(Value) total_sum FROM expenses) b

Answer 2

您可以在查询中使用 window 函数 SUM() 来计算 table:

的总数 value

SELECT [Expense Category],
       SUM(Value) sum_value, 
       100.0 * SUM(Value) / SUM(SUM(Value)) OVER () percentage
FROM expenses
WHERE Year = 2021
GROUP BY [Expense Category]
ORDER BY SUM(Value) DESC;

SQLite 显示 SUM 占总 SUM 的百分比

SQLite showing a percentage of a SUM from total SUM

sqlite

group-by

sum

window-functions