Question

我使用sql server，我有表：

tbl_GroupUser:
user_id, group_id

这是一个包含用户及其所在组的表（每个组都有多个user_id，每个用户都有多个组）。

tbl_group:
id, name

tbl_User:
id, age,....(information about the user)

tbl_Group的id与group_id之间以及tbl_User的id与user_id之间存在一对多的关系。

我创建了一个查询，返回特定用户只有2个用户的组的百分比，我想要一个返回所有用户结果的查询。这是我的查询：

SELECT cast((SELECT count(*) FROM 
(SELECT user_id FROM tbl_GroupUser WHERE group_id in 
(SELECT group_id FROM (SELECT t1.group_id, count(distinct t1.user_id) as numberOfUsers 
FROM tbl_GroupUser as t1 JOIN tbl_GroupUser as t2 ON t1.group_id = t2.group_id group by
t1.group_id) y WHERE y.numberOfUsers = 2)) as x WHERE x.user_id = 'user') as decimal) * 100 /
(SELECT count(*) FROM tbl_GroupUser WHERE user_id = 'user')

这意味着，计算用户所在的所有组，其中包含2个用户，并将其除以用户所在的组总数。

我想要的一个例子：

tbl_GroupUser：

group_id | user_id
------------------
 1       | 1
 1       | 2
 2       | 1

结果：

user_id | p_Grp2
----------------
 1      | 50.0
 2      | 100.0

Answer 1

简单创建用户定义功能并在选择查询中使用

  alter function UDF_GetPercentage(@UserId int)
returns decimal(18,10)
as begin 

declare @Percentage decimal(18,10)
SELECT @Percentage = cast(
(SELECT count(*) FROM 
(SELECT user_id FROM tbl_GroupUser WHERE group_id in 
(SELECT group_id FROM (SELECT t1.group_id, count(distinct t1.user_id) as numberOfUsers 
FROM tbl_GroupUser as t1 JOIN tbl_GroupUser as t2 ON t1.group_id = t2.group_id group by
t1.group_id) y 
WHERE y.numberOfUsers = 2)
)
as x

WHERE x.user_id in (@UserId)
) as decimal)
* 100 
/
(SELECT count(*) FROM tbl_GroupUser WHERE user_id in (@UserId ))

return @Percentage

end

并在像这样的选择查询中使用

SELECT   user_id, dbo.UDF_GetPercentage(user_id) as p_Grp2
FROM     tbl_GroupUser
group by user_id

Answer 2

你不是在尝试这么简单吗？

SELECT user_id, 100.0/COUNT(0) as p_Grp
FROM tbl_User u
INNER JOIN tbl_GroupUser gu ON gu.userId = u.Id
GROUP BY user_id;

Answer 3

使用窗口功能实时计算组成员，然后按用户聚合数据：

function cancelBtn() {
    return (
        <Form.Btn type={ this.props.closeBtnType || 'secondary-outline' }
                  size={ this.props.closeBtnSize || 'lg' }
                  key="cancelBtn"
                  onClick={ this.props.closeBtnAction ? this.doCloseAction.bind(this) : this.close.bind(this) }
        >{ this.props.closeBtnText || 'Cancel' }</Form.Btn>
    );
}

SQL更改查询以返回所有用户的结果

3 个答案: