ALTER USER -- Modifies user account information
ALTER USER username
[ WITH PASSWORD 'password ' ]
[ CREATEDB | NOCREATEDB ]
[ CREATEUSER | NOCREATEUSER ]
[ VALID UNTIL 'abstime ' ]
ALTER USER is used to change the attributes of a user's Postgres account. Only a database superuser can change privileges and password expiration with this command. Ordinary users can only change their own password.
Use CREATE USER to create a new user and DROP USER to remove a user.
Change a user password:
ALTER USER davide WITH PASSWORD 'hu8jmn3';
Change a user's valid until date:
ALTER USER manuel VALID UNTIL 'Jan 31 2030';
Change a user's valid until date, specifying that his authorization
should expire at midday on 4th May 1998 using the time zone which
is one hour ahead of UTC:
ALTER USER chris VALID UNTIL 'May 4 12:00:00 1998 +1';
Give a user the ability to create other users and new databases:
ALTER USER miriam CREATEUSER CREATEDB;
There is no ALTER USER statement in SQL92. The standard leaves the definition of users to the implementation.