具有多个表的复杂MySQL查询(有关更多详细信息,请阅读)
我有4个表:团队、用户、用户团队和权限:具有多个表的复杂MySQL查询(有关更多详细信息,请阅读),mysql,multiple-tables,Mysql,Multiple Tables,我有4个表:团队、用户、用户团队和权限: PermissionsID | Name ------------------------------- 1 | Read Comments 2 | Write Comments 3 | Send Email 4 | Admin 用户: UserID | Name ------------------------ 1 | John 2 |
PermissionsID | Name
-------------------------------
1 | Read Comments
2 | Write Comments
3 | Send Email
4 | Admin
用户:
UserID | Name
------------------------
1 | John
2 | Mike
3 | Tom
小组:
TeamID | Name
-------------------------------
1 | FC Barcelona
2 | Real Madrid
3 | Manchester United
4 | Liverpool
权限:
PermissionsID | Name
-------------------------------
1 | Read Comments
2 | Write Comments
3 | Send Email
4 | Admin
用户团队:
ID | UserID | TeamID | PermissionID
--------------------------------------------
1 | 1 | 1 | 1
2 | 1 | 1 | 2
3 | 1 | 1 | 4
4 | 1 | 2 | 1
4 | 1 | 4 | 3
-
-
UserID=1(我们在查询之前就知道这一点)
我想进行查询以获得如下内容:
Permission.Name | FC Barcelona | Real Madrid | Manchester United | Liverpool | etc...
----------------------------------------------------------------------------
Read Comments | (something) | (something) | NULL | NULL
Write Comments | (something) | NULL | NULL | NULL
Send Email | NULL | NULL | NULL | (something)
Admin | (something) | NULL | NULL | NULL
Permission | Team | User_name | User_id
-----------------------------------------------------------------
Read Comments | FC Barcelona | John | 1
Write Comments | Real Madrid | John | 1
Send Email | Manchester United | Mike | 2
Admin | ...(unlimited) | Tom | 2
团队的数量不受限制
有什么想法吗?我不介意有多个问题
提前谢谢
解决方案
仅限首批选定团队:
SELECT TeamID, name FROM Teams
然后使用团队数据创建一个新查询:
SELECT
Permissions.name as 'permissionName',
<Loop this line with the previous query>
MAX(CASE WHEN Teams.name = 'FC Barcelona' THEN Teams.name ELSE NULL END) AS 'FC Barcelona'
<End loop>
FROM Permissions
LEFT JOIN UserTeams ON UserTeams.PermissionID = Permissions.PermissionID AND UserTeams.UserID = '1'
LEFT JOIN Teams ON Teams.TeamID = UserTeams.TeamID
GROUP BY Permissions.name
选择
Permissions.name作为“permissionName”,
最大值(当Teams.name='FC Barcelona'然后Teams.name ELSE为NULL END时为'FC Barcelona'
来自权限
在UserTeams.PermissionID=Permissions.PermissionID和UserTeams.UserID='1'上左键加入UserTeams
左加入Teams.TeamID=UserTeams.TeamID上的团队
按权限分组。名称
现在我们得到了我们想要的结果。我认为你们的表格不完整。。其中将存储“(something)”查询结果中的列数不是可变的,您将始终获得相同的列数。因此,我建议使用如下查询结果:
Permission.Name | FC Barcelona | Real Madrid | Manchester United | Liverpool | etc...
----------------------------------------------------------------------------
Read Comments | (something) | (something) | NULL | NULL
Write Comments | (something) | NULL | NULL | NULL
Send Email | NULL | NULL | NULL | (something)
Admin | (something) | NULL | NULL | NULL
Permission | Team | User_name | User_id
-----------------------------------------------------------------
Read Comments | FC Barcelona | John | 1
Write Comments | Real Madrid | John | 1
Send Email | Manchester United | Mike | 2
Admin | ...(unlimited) | Tom | 2
(当然有正确的值;))
对此的SQL查询将是:
SELECT
p.Name AS Permission,
u.Name AS User_name,
t.Name AS Team,
u.id AS User_id
FROM
UserTeams AS ut
INNER JOIN
Users AS u ON (ut.UserId = u.UserId)
INNER JOIN
Teams AS t ON (ut.TeamId = t.TeamId)
INNER JOIN
Permissions AS p ON (ut.PermissionId = p.PermissionsId)
WHERE
u.UserID = :userId
阅读数据透视表:数据透视表的问题是使这些数据透视表成为动态的……如果对行/列有权限,(something)值可以是任何值。如果没有权限,则行/列为空。。。如果我需要为所选用户(UserID=1)获取每个团队的权限列表,这会有什么帮助?
permissions=array()
foreach($result as$row){
`permissions[$row['user\u id'][$row['team'][$row['Permission']]=$row['Permission'];}
现在您有了一个数组,可以用foreach进行迭代了。。。这是最好的解决方案,因为您只需要一个查询