Question

SELECT User, COUNT(*) as count FROM Tests WHERE Release = '1.0' GROUP by User;

以上查询将返回不同的数字，但是，我想将计数转换为与总记录数相关的百分数。考虑WHERE子句的记录总数。

Answer 1

SELECT R1.user, COUNT(*)/R2.COUNT_ALL AS Expr1
  FROM Releases R1,
       (SELECT COUNT(*) As COUNT_ALL FROM Releases WHERE Release = '1.0') R2
 WHERE R1.Release = '1.0'
 GROUP BY R1.user, R2.COUNT_ALL

Answer 2

这是使用单个SELECT的另一种方法：

SELECT 
    Tests.User, 
    Count(IIf([Tests].[Release]='1.0', 1, Null)) / Count(*) AS Percentage
FROM 
    Tests
GROUP BY 
    Tests.User

与之前建议的方法不同，无论是好还是坏，这个方法都会为测试中没有记录的用户返回记录，其中Release为“1.0”。如果您不想要这些记录，可以添加一个HAVING子句来消除它们。

希望这有帮助。

Answer 3

与Brian的答案相似，但仅限于标准SQL而不是MS Access。（也可以COUNT使用SUM代替NULL，0 SELECT Tests.User, Sum(CASE WHEN Release='1.0' THEN 1 ELSE 0 END) / Count(*) AS Percentage FROM Tests GROUP BY Tests.User。{/ p>

{{1}}

在SQL查询中计算内联百分比

3 个答案: