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$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_user.sgml,v 1.17 2001/09/21 20:31:45 tgl Exp $
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<refentry id="SQL-ALTERUSER">
 <refmeta>
  <refentrytitle id="sql-alteruser-title">
   ALTER USER
  </refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>
 <refnamediv>
  <refname>
   ALTER USER
  </refname>
  <refpurpose>
   change a database user account
  </refpurpose>
 </refnamediv>
 <refsynopsisdiv>
  <refsynopsisdivinfo>
   <date>2001-07-10</date>
  </refsynopsisdivinfo>
  <synopsis>
ALTER USER <replaceable class="PARAMETER">username</replaceable> [ [ WITH ] <replaceable class="PARAMETER">option</replaceable> [ ... ] ]

where <replaceable class="PARAMETER">option</replaceable> can be:

	  [ ENCRYPTED | UNENCRYPTED ] PASSWORD '<replaceable class="PARAMETER">password</replaceable>' 
        | CREATEDB | NOCREATEDB
        | CREATEUSER | NOCREATEUSER 
        | VALID UNTIL '<replaceable class="PARAMETER">abstime</replaceable>'
  </synopsis>

  <refsect2 id="R2-SQL-ALTERUSER-1">
   <refsect2info>
    <date>1998-09-08</date>
   </refsect2info>
   <title>
    Inputs
   </title>

   <para>
    <variablelist>
     <varlistentry>
      <term><replaceable class="PARAMETER">username</replaceable></term>
      <listitem>
       <para>
	The name of the user whose details are to be altered.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="PARAMETER">password</replaceable></term>
      <listitem>
       <para>
	The new password to be used for this account.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term>ENCRYPTED</term>
      <term>UNENCRYPTED</term>
      <listitem>
       <para> 
	These keywords control whether the
	password is stored encrypted in <literal>pg_shadow</>.  (See
	<xref linkend="SQL-CREATEUSER" endterm="SQL-CREATEUSER-title">
	for more information about this choice.)
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term>CREATEDB</term>
      <term>NOCREATEDB</term>
      <listitem>
       <para> 
	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.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term>CREATEUSER</term>
      <term>NOCREATEUSER</term>
      <listitem>
       <para>
	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.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="PARAMETER">abstime</replaceable></term>
      <listitem>
       <para>
	The date (and, optionally, the time)
	at which this user's password is to expire.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
  </refsect2>
    
  <refsect2 id="R2-SQL-ALTERUSER-2">
   <refsect2info>
    <date>1998-09-08</date>
   </refsect2info>
   <title>
    Outputs
   </title>
   <para>
    <variablelist>
     <varlistentry>
      <term><computeroutput>ALTER USER</computeroutput></term>
      <listitem>
       <para>
	Message returned if the alteration was successful.
       </para>
      </listitem>
     </varlistentry>
     
     <varlistentry>
      <term><computeroutput>
ERROR:  ALTER USER: user "username" does not exist
       </computeroutput></term>
      <listitem>
       <para>
	Error message returned if the specified user is not known to
	the database.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
  </refsect2>
 </refsynopsisdiv>

 <refsect1 id="R1-SQL-ALTERUSER-1">
  <refsect1info>
   <date>1998-09-08</date>
  </refsect1info>
  <title>
   Description
  </title>
  <para>
   <command>ALTER USER</command> is used to change the attributes of a user's
   <productname>Postgres</productname> account.  Attributes not mentioned
   in the command retain their previous settings.
  </para>
  <para>
   Only a database superuser
   can change privileges and password expiration with this command. Ordinary
   users can only change their own password.
  </para>
  <para>
   <command>ALTER USER</command> cannot change a user's group memberships.
   Use <xref linkend="SQL-ALTERGROUP" endterm="SQL-ALTERGROUP-title">
   to do that.
  </para>
  <para>
   Use <xref linkend="SQL-CREATEUSER" endterm="SQL-CREATEUSER-title">
   to create a new user and <xref linkend="SQL-DROPUSER"
   endterm="SQL-DROPUSER-title"> to remove a user.
  </para>
 </refsect1>

 <refsect1 id="R1-SQL-ALTERUSER-2">
  <title>
   Usage
  </title>
  <para>
   Change a user password:

<programlisting>
ALTER USER davide WITH PASSWORD 'hu8jmn3';
</programlisting>

   Change a user's valid until date:

<programlisting>
ALTER USER manuel VALID UNTIL 'Jan 31 2030';
</programlisting>

   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:
<programlisting>
ALTER USER chris VALID UNTIL 'May 4 12:00:00 1998 +1';
</programlisting>

   Give a user the ability to create other users and new databases:

<programlisting>
ALTER USER miriam CREATEUSER CREATEDB;
</programlisting>

  </para>
 </refsect1>

 <refsect1 id="R1-SQL-ALTERUSER-3">
  <title>
   Compatibility
  </title>
    
  <refsect2 id="R2-SQL-ALTERUSER-4">
   <refsect2info>
    <date>1998-09-08</date>
   </refsect2info>
   <title>
    SQL92
   </title>
   <para>
    There is no <command>ALTER USER</command> statement in
    <acronym>SQL92</acronym>.
    The standard leaves
    the definition of users to the implementation.
   </para>
  </refsect2>
 </refsect1>
</refentry>

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