I have two tables User and UserRoles in sql server. User table  has basic user information e.g. UserId,Name etc and UserRoles has columns like UserId,RoleName. There is one to many relationship between these two tables i.e. one User can have multiple roles. 
User
UserId  Name
1       A
2       B
3       C
UserRoles
UserId  Rolename
1       Manager
1       Event Organiser
2       Supervisor
2       Employee
2       Some otherRole
I need to write a query in sql which will return like following. i.e concatenate one to many records into a single string
UserId  Roles
1       Manager,Event Organiser
2       Supervisor,Employee,Some otherRole
 
     
     
    