Question

我想找到完成所有相关任务的所有未完成的请求。在这些请求中找到最新完成的任务用户电子邮件。也就是说，我需要返回RequestID，TaskID，UpdatedDate，email

这是我的疑问：

select r.RequestID,r.UpdatedDate,u.Email
from Request r 
left outer join Task t1 on r.RequestID = t1.RequestID
left outer join Task t2 on r.RequestID = t2.RequestID and t2.UpdatedDate > t1.UpdatedDate
left outer join Users u on t1.AssignedEmp = u.UserID
where r.RequestStatusID in (2,6) and t1.TaskStatusID in (2,5)
and t2.RequestID is null

此查询为我提供了每个请求的最新完成或取消任务，但同一请求中还有其他任务尚未完成。例如这些记录：

RequestID = 1
TaskID = 1, TaskStatusID = 2 (completed) UpdatedDate = '20150417'
TaskID = 2, TaskStatusID = 3 (InProgress)UpdatedDate = '20150416'

将选择此请求。但我不想要它。我想要所有TaskStatusID =已完成或已取消

我该如何解决？谢谢！

Answer 1

尝试使用相关的not exists子查询来过滤掉至少有一个未完成任务的请求。使用apply获取最近更新任务的电子邮件。

select
    r.RequestID,
    r.UpdatedDate,
    u.Email
from Request as r
cross apply (
    select top (1) u.Email
    from Task as t
    inner join Users as u
    on t.AssignedEmp = u.UserID
    where t.RequestID = r.RequestID
    order by r.UpdatedDate desc
) as u /* the user associated with the most recently updated task */
where not exists (
    select *
    from Task as t
    where t.RequestID = r.RequestID
    and t.TaskStatusID <> 2
) /* a not completed task does not exist */
and r.RequestStatusID <> 2 /* the request is not completed */

Answer 2

您可以在ranking function (ROW_NUMBER)

中使用CTE

;WITH C AS(
    SELECT  ROW_NUMBER() OVER (ORDER BY t.RequestID, t.UpdatedDate DESC) AS Rn
            ,r.RequestID
            ,t.TaskID
            ,r.UpdatedDate
            ,u.Email
    FROM Request AS r
    LEFT JOIN Task AS t ON t.RequestId = r.RequestId
    LEFT JOIN Users AS u ON u.UserId = t.AssignedEmp
    WHERE r.RequestStatusID IN (2,6)
    AND t.TaskStatusID IN(2, 5)
)
SELECT RequestID, TaskID, UpdatedDate, Email
FROM C
WHERE Rn = 1

Answer 3

最后我解决了这个问题...

select r.RequestID, 
t.UpdatedOn, u.FirstName + ' ' + u.LastName as UserName, u.Email
from Request r
join
    (

    select RequestID,AssignedEmp, TaskID, Row_Number() OVER (Partition By RequestID Order By UpdatedDate desc) AS RowNo , UpdatedDate, TaskStatusID
    from Task
    where RequestID not in ( select t1.RequestID
                    from Task t1
                    where t1.TaskStatusID not in (2,5)
                    group by t1.RequestID, t1.TaskID
                    )
    ) t                 
on r.RequestID = t.RequestID and t.RowNo = 1
and r.RequestStatusID in (2,6)
join Users u on t.AssignedEmp = u.UserID
order by r.RequestID desc

查找所有子表值满足要求的父级

3 个答案: