HAS_ROLE

Indicates, with a Boolean value, whether a role has been assigned to a user. This function is useful for letting you check your own role membership.

Behavior Type

Stable

Syntax 1

HAS_ROLE( [ 'user_name' ,] 'role_name' );

Syntax 2

HAS_ROLE( 'role_name' );

Parameters

user_name

[Optional] The name of a user to look up. Currently, only a superuser can supply the user_name argument.

 
role_name

The name of the role you want to verify has been granted.

Privileges

Users can check their own role membership by calling HAS_ROLE('role_name'), but only a superuser can look up other users' memberships using the optional user_name parameter.

Notes

You can query V_CATALOG system tables ROLES, GRANTS, and USERS to show any directly-assigned roles; however, these tables do not indicate whether a role is available to a user when roles may be available through other roles (indirectly).

Examples

User Bob wants to see if he has been granted the commentor role:

=> SELECT HAS_ROLE('commentor');

Output t for true indicates that Bob has been assigned the commentor role:

 HAS_ROLE
----------
 t
(1 row)

In the following function call, a superuser checks if the logadmin role has been granted to user Bob:

=> SELECT HAS_ROLE('Bob', 'logadmin'); 
 HAS_ROLE
----------
 t
(1 row)

To view the names of all roles users can access, along with any roles that have been assigned to those roles, query the V_CATALOG.ROLES system table. An asterisk in the output means role granted WITH ADMIN OPTION.

=> SELECT * FROM roles;       
      role_id      |      name       | assigned_roles
-------------------+-----------------+----------------
 45035996273704964 | public          |
 45035996273704966 | dbduser         |
 45035996273704968 | dbadmin         | dbduser*
 45035996273704972 | pseudosuperuser | dbadmin*
 45035996273704974 | logreader       |
 45035996273704976 | logwriter       |
 45035996273704978 | logadmin        | logreader, 
                                       logwriter
(7 rows)

See Also