Mysql 在SQL中连接三个表_Mysql_Sql

Mysql 在SQL中连接三个表

mysql sql

Mysql 在SQL中连接三个表,mysql,sql,Mysql,Sql,好吧，这似乎太容易了，但我们都没有得到想要的结果，结果应该是这样的： User uid name Roles uid role_id Subscriptions uid subscriptions_id user roles subscriptions 1 2,3 1,4,5 2 2,4 4,5,6 .... user roles subscriptions 1 2,3 5 2 2,4 6 .... SELECT User.name,

好吧，这似乎太容易了，但我们都没有得到想要的结果，结果应该是这样的：

User
uid name

Roles
uid role_id

Subscriptions
uid subscriptions_id

user roles subscriptions
1    2,3   1,4,5
2    2,4   4,5,6
....

user roles subscriptions
1    2,3   5
2    2,4   6
....

SELECT User.name, 
       GROUP_CONCAT(Roles.role_id), 
       GROUP_CONCAT(Subscriptions.subscriptions_id) 
FROM   User 
       LEFT JOIN Roles ON User.uid = Roles.uid 
       LEFT JOIN Subscriptions ON Users.uid = Subscriptions.uid

相反，结果如下所示：

User
uid name

Roles
uid role_id

Subscriptions
uid subscriptions_id

user roles subscriptions
1    2,3   1,4,5
2    2,4   4,5,6
....

user roles subscriptions
1    2,3   5
2    2,4   6
....

SELECT User.name, 
       GROUP_CONCAT(Roles.role_id), 
       GROUP_CONCAT(Subscriptions.subscriptions_id) 
FROM   User 
       LEFT JOIN Roles ON User.uid = Roles.uid 
       LEFT JOIN Subscriptions ON Users.uid = Subscriptions.uid

select命令如下所示：

User
uid name

Roles
uid role_id

Subscriptions
uid subscriptions_id

user roles subscriptions
1    2,3   1,4,5
2    2,4   4,5,6
....

user roles subscriptions
1    2,3   5
2    2,4   6
....

SELECT User.name, 
       GROUP_CONCAT(Roles.role_id), 
       GROUP_CONCAT(Subscriptions.subscriptions_id) 
FROM   User 
       LEFT JOIN Roles ON User.uid = Roles.uid 
       LEFT JOIN Subscriptions ON Users.uid = Subscriptions.uid

顺便说一句，小组讨论不是问题。如果我不考虑这一点，我仍然会得到这样的结果：

User
uid name

Roles
uid role_id

Subscriptions
uid subscriptions_id

user roles subscriptions
1    2,3   1,4,5
2    2,4   4,5,6
....

user roles subscriptions
1    2,3   5
2    2,4   6
....

SELECT User.name, 
       GROUP_CONCAT(Roles.role_id), 
       GROUP_CONCAT(Subscriptions.subscriptions_id) 
FROM   User 
       LEFT JOIN Roles ON User.uid = Roles.uid 
       LEFT JOIN Subscriptions ON Users.uid = Subscriptions.uid

而不是

user roles subscriptions
1    2     5
1    3     5
2    2     6

我试过这个：

user roles subscriptions
1    2     1
1    3     4
1    -     5

我得到了这个：

SELECT User.uid, 
       GROUP_CONCAT(DISTINCT Roles.role_id), 
       GROUP_CONCAT(DISTINCT Subscriptions.subscriptions_id)
FROM   User 
       LEFT JOIN Roles ON User.uid = Roles.uid 
       LEFT JOIN Subscriptions ON User.uid = Subscriptions.uid
GROUP BY User.uid

这是你的结果吗

user    roles    subscriptions
1       2,3      1,5,4
2       2,4      4,5,6