Question

我正在开发一个内部网Web应用程序，为用户提供简短的测验。测验将通过电子邮件发送给用户。我有以下数据库设计：

员工表：用户名，姓名，职位，分部ID

分区表：DivisionID，DivisionName

测验表：QuizID，标题，描述，IsSent

UserQuiz表：UserQuizID，Score，DateTimeComplete，QuizID，Username

注意：每个表中的第一个属性是主键。

对于您的信息，IsSent是一个标志，用于确定向用户发送哪个测验以及哪个测验不是。

我现在需要和需要的是：我需要提出一个查询，显示上次发送测验中非参与者的姓名。这意味着如果有多个测验发送给用户，则此查询应显示上次发送测验中非参与者的姓名。该查询也应该显示DivisionName。

我想出了以下查询，但它显示了数据库中所有测验中的非参与者。那么如何修改呢？或者如何获得上述要求？

SELECT     TOP (100) PERCENT Q.Title, D.DivisionShortcut, E.Name
FROM         dbo.Quiz AS Q CROSS JOIN
                      dbo.employee AS E LEFT OUTER JOIN
                      dbo.Divisions AS D ON E.DivisionCode = D.SapCode
WHERE     (NOT EXISTS
                          (SELECT     UserQuizID, QuizID, DateTimeComplete, Score, Username
                            FROM          dbo.UserQuiz AS UQ
                            WHERE      (Username = E.Username) AND (QuizID = Q.QuizID)))
ORDER BY Q.Title, D.DivisionShortcut

Answer 1

最后发送的测验是

select max(quizID) from dbo.Quiz where IsSent = 1

参与最后一次测验的用户：

select A.QuizID, a.Username 
from UserQuiz a join 
 (select max(quizID) quizID from dbo.Quiz where IsSent = 1) b
  on a.QuizId = b.quizID

未参加上一次测验的用户

select u.name, d.DivisionName
from
  users u
  join Divisions d on (u.divisionID = d.divisionID)
  left join 
    (select A.QuizID, a.Username 
     from UserQuiz a join 
     (select max(quizID) quizID from dbo.Quiz where IsSent = 1) b
     on a.QuizId = b.quizID
     ) c
   on u.username = c.username
 where c.QuizID is null

Answer 2

我不是使用相关子查询（为每个行执行，因此执行效果不佳），而是使用NOT IN来表达它，并简化整个事情，像这样：

SELECT Q.Title, D.DivisionShortcut, E.Name
FROM (
    SELECT Title, QuizID
    FROM UserQuiz
    WHERE QuizID = (SELECT MAX(QuizID) FROM UserQuiz)) Q
CROSS JOIN employee E
JOIN Divisions D ON E.DivisionCode = D.SapCode
WHERE E.Username NOT IN (
    SELECT Username
    FROM UserQuiz
    WHERE QuizID = Q.QuizID)
ORDER BY Q.Title, D.DivisionShortcut

Answer 3

尝试：

select q.Title, d.DivisionShortcut, e.Name
from (select top 1 * from Quiz where IsSent = 1 order by QuizID desc) q
cross join Employee e
join Division d on e.divisionID = d.divisionID
where not exists
(select null from UserQuiz uq
 where uq.QuizID = q.QuizID and uq.Username = e.Username)

如何在每个部门的最后一次发送测验中显示非参与者的姓名？

3 个答案: