Add an inner join to mySQL GROUP_CONCAT statement

Laurence picture Laurence · Apr 10, 2012 · Viewed 7.3k times · Source

Problem: I have a GROUP_CONCAT query that is working as intended, except I'd like to make the concat a joined answer, not the raw ID field.

Current query:

SELECT user.user_id, user.user, GROUP_CONCAT(user_roles.roleID separator ', ') roles
FROM user
JOIN user_roles ON user.user_ID = user_roles.user_ID
GROUP BY users.user_ID, users.user

Gives result:

+----------+---------+----------------------------+
|  user_ID | user    |   roles                    |
+----------+---------+----------------------------+
|        1 |   Smith |    1, 3                    |
+----------+---------+----------------------------+
|        2 |   Jones |    1, 2, 3                 |
+----------+---------+----------------------------+

Desired result:

+----------+---------+----------------------------+
|  user_ID | user    |   roles                    |
+----------+---------+----------------------------+
|        1 |   Smith |    Admin, Other            |
+----------+---------+----------------------------+
|        2 |   Jones |    Admin, Staff, Other     |
+----------+---------+----------------------------+

User table:

+----------+---------+
|  user_ID | user    |
+----------+---------+
|        1 |   Smith |
+----------+---------+
|        2 |   Jones |
+----------+---------+

*users_roles table:*

+----------+---------+
|  user_ID | role_ID |
+----------+---------+
|        1 |   1     |
+----------+---------+
|        2 |   1     |
+----------+---------+
|        2 |   2     |
+----------+---------+
|        2 |   3     |
+----------+---------+
|        1 |   3     |
+----------+---------+

roles table:

+----------+-----------+
|  role_ID | role_name |
+----------+-----------+
|        1 |   Admin   |
+----------+-----------+
|        2 |   Staff   |
+----------+-----------+
|        3 |   Other   |
+----------+-----------+

Answer

Vikram picture Vikram · Apr 10, 2012

try the following query

SELECT user.user_id, user.user, GROUP_CONCAT(roles.role_name  separator ', ') roles
FROM user
JOIN user_roles ON user.user_ID = user_roles.user_ID
JOIN roles ON user_roles.role_ID= user_roles.role_ID
GROUP BY users.user_ID, users.user