Changes a role name or membership.
ALTER GROUP <role_specification> ADD USER <user_name> [, ... ]
ALTER GROUP <role_specification> DROP USER <user_name> [, ... ]
where <role_specification> can be:
<role_name>
| CURRENT_USER
| SESSION_USER
ALTER GROUP <group_name> RENAME TO <new_name>
ALTER GROUP
changes the attributes of a user group. This is an obsolete command, though still accepted for backwards compatibility, because users and groups are superseded by the more general concept of roles.
The first two variants add users to a group or remove them from a group. (Any role can play the part of either a "user" or "group" for this purpose. These variants are effectively equivalent to granting or revoking membership in the role named as the "group"; so, the preferred way to do this is to use GRANT or REVOKE.
The third variant changes the name of the group. This is exactly equivalent to renaming the role with ALTER ROLE.
ALTER GROUP
does not create or drop users.
To add users to a group:
ALTER GROUP staff ADD USER karl, john;
To remove a user from a group:
ALTER GROUP workers DROP USER beth;
There is no ALTER GROUP
statement in the SQL standard.
Parent topic: SQL Commands