ALTER GROUP groupname ADD USER username [, ... ] ALTER GROUP groupname DROP USER username [, ... ] ALTER GROUP groupname RENAME TO newname
ALTER GROUP changes the attributes of a user group.
The first two variants add users to a group or remove them from a group. Only database superusers can use this command.
The third variant changes the name of the group. Only a database superuser can rename groups.
The name of the group to modify.
Users that are to be added to or removed from the group. The users must already exist; ALTER GROUP does not create or drop users.
The new name of the group.
Add users to a group:
ALTER GROUP staff ADD USER karl, john;
Remove a user from a group:
ALTER GROUP workers DROP USER beth;
There is no ALTER GROUP statement in the SQL standard. The concept of roles is similar.