Question

我有三个表（这些是相关列）：

Table1
bookingid, person, role


Table2
bookingid, projectid


Table3
projectid, project, numberofrole1, numberofrole2

Table1.role可以采用两个值：“role1”或“role2”。

我想要做的是在表1中显示哪些项目不具有正确数量的角色。每个角色应该有的角色数量见表3.

例如，如果Table1包含这三行：

bookingid, person, role
7, Tim, role1
7, Bob, role1,
7, Charles, role2

和表2

bookingid, projectid
7, 1

和表3

projectid, project, numberofrole1, numberofrole2
1, Test1, 2, 2

我希望结果显示项目 Test1 没有正确数量的 role2s 。

老实说，这样的事情有点超出我的能力范围，所以我愿意接受最佳方法的建议。我正在使用sqlite和php（它只是一个小项目）。我想，一旦我得到了我的结果，我可以在最后用php做些什么，但我想知道是否有更好的方法来使用sqlite。

我开始做这样的事情：

SELECT project, COUNT(numberofrole1) as "Role"
FROM Table1
JOIN Table2
USING (projectid)
JOIN Table3
USING (bookingid)
WHERE role="role1"
GROUP BY project

但我无法弄清楚如何将返回的值作为“角色”与从numberofrole1获得的值进行比较

感谢任何帮助。

Answer 1

试试这个：

Select * From Table3 t3
Where (Select Count(*) From Table1 t1r1
          Join Table2 t2r1 On t2r1.bookingid = t1r1.bookingid
       Where t2r1.projectid = t3.ProjectId
          And role = 'role1') <>  numberofrole1 
     Or
     (Select Count(*) From Table1 t1r2
          Join Table2 t2r2 On t2r2.bookingid = t1r2.bookingid
       Where t2r2.projectid = t3.ProjectId
          And role = 'role2') <>  numberofrole2

甚至更好，如果它有效......（尝试一下）

Select * From Table3 t3
Where Exists 
      (Select * From Table1 t1r1
          Join Table2 t2r1 
               On t2r1.bookingid = t1r1.bookingid
       Where t2r1.projectid = t3.ProjectId
       Group By Role
       Having Sum(Case Role When 'role1' Then 1 Else 0 End) 
                              = t3.numberofrole1
          And Sum(Case Role When 'role2' Then 1 Else 0 End)  
                              = t3.numberofrole2 )

Answer 2

SELECT * FROM
(
  SELECT 
    projectid, 
    role,
    CASE WHEN role = 'role2' THEN numberofrole2 DEFAULT numberofrole1 END numRequired,
    COUNT(*) numPresent
  FROM Table1 
  JOIN Table2 ON Table1.bookingid = Table2.bookingid
  JOIN Table3 ON Table2.projectid = Table3.projectid
  GROUP BY projectid, role
)
WHERE numRequired > numPresent

Answer 3

尝试类似的东西：

SELECT
    projectid, 
    numberofrole1,
    numberofrole2,
    SUM(role='role1') as actual_numberofrole1,
    SUM(role='role2') as actual_numberofrole2
FROM table3
JOIN table2
    USING (projectid)
JOIN table1
    USING (bookingid)
GROUP BY projectid
HAVING numberofrole1 <> actual_numberofrole1
    OR numberofrole2 <> actual_numberofrole2

用于显示从另一列检索的值的count（）的SQL代码

3 个答案: