ALTER USER
SQL - Language Statements
ALTER USER
change a database user account
ALTER USER
ALTER USER name [ [ WITH ] option [ ... ] ]
where option can be:
CREATEDB | NOCREATEDB
| CREATEUSER | NOCREATEUSER
| [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password'
| VALID UNTIL 'abstime'
ALTER USER name RENAME TO newname
ALTER USER name SET parameter { TO | = } { value | DEFAULT }
ALTER USER name RESET parameter
Description
ALTER USER changes the attributes of a
PostgreSQL user account. Attributes not
mentioned in the command retain their previous settings.
The first variant of this command listed in the synopsis changes certain
per-user privileges and authentication settings. (See below for
details.) Database superusers can change any of these settings for any
user. Ordinary users can only change their own password.
The second variant changes the name of the user. Only a database
superuser can rename user accounts. The current session user cannot be
renamed. (Connect as a different user if you need to do that.)
Because MD5>-encrypted passwords use the user name as
cryptographic salt, renaming a user clears their MD5>
password.
The third and the fourth 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 command line.
Ordinary users can change their own session defaults.
Superusers can change anyone's session defaults.
Certain variables cannot be set this way, or can only be
set by a superuser.
Parameters
name
The name of the user whose attributes are to be altered.
CREATEDB
NOCREATEDB
These clauses define a user's ability to create databases. If
CREATEDB is specified, the user
will be allowed to create his own databases. Using
NOCREATEDB will deny a user the ability to
create databases. (If the user is also a superuser, then this
setting has no real effect.)
CREATEUSER
NOCREATEUSER
These clauses determine whether a user will be permitted to
create new users himself. CREATEUSER will also make
the user a superuser, who can override all access restrictions.
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
for more information about this choice.)
abstime
The date (and, optionally, the time)
at which this user's password is to expire. To set the password
never to expire, use 'infinity'>.
newname
The new name of the user.
parameter
value
Set this user's session default for the specified configuration
parameter to the given value. If
value is DEFAULT
or, equivalently, RESET is used, the
user-specific variable setting is removed, so the user will
inherit the system-wide default setting in new sessions. Use
RESET ALL to clear all user-specific settings.
See and for more information about allowed
parameter names and values.
Notes
Use
to add new users, and to remove a user.
ALTER USER cannot change a user's group memberships.
Use
to do that.
The VALID UNTIL> clause defines an expiration time for a
password only, not for the user account per se>. In
particular, the expiration time is not enforced when logging in using
a non-password-based authentication method.
It is also possible to tie a
session default to a specific database rather than to a user; see
.
User-specific settings override database-specific
ones if there is a conflict.
Examples
Change a user's password:
ALTER USER davide WITH PASSWORD 'hu8jmn3';
Change the expiration date of the user's password:
ALTER USER manuel VALID UNTIL 'Jan 31 2030';
Change a password expiration date, specifying that the password
should expire at midday on 4th May 2005 using
the time zone which is one hour ahead of UTC>:
ALTER USER chris VALID UNTIL 'May 4 12:00:00 2005 +1';
Make a password valid forever:
ALTER USER fred VALID UNTIL 'infinity';
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.
See Also