ALTER USER username [ [ WITH ] option [ ... ] ]
where option can be:
[ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password'
| CREATEDB | NOCREATEDB
| CREATEUSER | NOCREATEUSER
| VALID UNTIL 'abstime'
ALTER USER username SET variable { TO | = } { value | DEFAULT }
ALTER USER username RESET variable
Description
ALTER USER is used to change the attributes of a
PostgreSQL user account. Attributes not
mentioned in the command retain their previous settings.
The first variant of this command in the synopsis changes certain
global user privileges and authentication settings. (See below for
details.) Only a database superuser can change privileges and
password expiration with this command. Ordinary users can only
change their own password.
The second and the third variant change a user's session default for
a specified configuration variable. Whenever the user subsequently
starts a new session, the specified value becomes the session default,
overriding whatever setting is present in postgresql.conf
or has been received from the postmaster.
Ordinary users can change their own session defaults.
Superusers can change anyone's session defaults.
Parameters
username
The name of the user whose attributes are to be altered.
password
The new password to be used for this account.
ENCRYPTED UNENCRYPTED
These key words control whether the password is stored
encrypted in pg_shadow. (See
CREATE USER
for more information about this choice.)
CREATEDB NOCREATEDB
These clauses define a user's ability to create databases. If
CREATEDB is specified, the user being
defined will be allowed to create his own databases. Using
NOCREATEDB will deny a user the ability to
create databases.
CREATEUSER NOCREATEUSER
These clauses determine whether a user will be permitted to
create new users himself. This option will also make the user
a superuser who can override all access restrictions.
abstime
The date (and, optionally, the time)
at which this user's password is to expire.
variable value
Set this user's session default for the specified configuration
variable to the given value. If
value is DEFAULT
or, equivalently, RESET is used, the
user-specific variable setting is removed and the user will
inherit the system-wide default setting in new sessions. Use
RESET ALL to clear all settings.
See SET and the
Administrator's Guide for more
information about allowed variable names and values.
Diagnostics
ALTER USER
Message returned if the alteration was successful.
ERROR: ALTER USER: user "username" does not exist
Error message returned if the specified user is not known to
the database.
ALTER USER cannot change a user's group memberships.
Use ALTER GROUP
to do that.
Using ALTER DATABASE, it is also possible to tie a
session default to a specific database rather than a user.
Examples
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;
Compatibility
The ALTER USER statement is a
PostgreSQL extension. The SQL standard
leaves the definition of users to the implementation.
