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$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_group.sgml,v 1.9 2003/04/15 13:25:08 petere Exp $
PostgreSQL documentation
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<refentry id="SQL-ALTERGROUP">
 <refmeta>
  <refentrytitle id="SQL-ALTERGROUP-title">ALTER GROUP</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>ALTER GROUP</refname>
  <refpurpose>add users to a group or remove users from a group</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
ALTER GROUP <replaceable class="PARAMETER">groupname</replaceable> ADD USER <replaceable class="PARAMETER">username</replaceable> [, ... ]
ALTER GROUP <replaceable class="PARAMETER">groupname</replaceable> DROP USER <replaceable class="PARAMETER">username</replaceable> [, ... ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER GROUP</command> is used to add or remove users from a
   group. Only database superusers can use this command.
   Adding a user to a group does not create the user. Similarly, removing
   a user from a group does not drop the user itself.
  </para>

  <para>
   Use <xref linkend="SQL-CREATEGROUP" endterm="SQL-CREATEGROUP-title">
   to create a new group and <xref linkend="SQL-DROPGROUP"
   endterm="SQL-DROPGROUP-title"> to remove a group.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameter</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="PARAMETER">groupname</replaceable></term>
    <listitem>
     <para>
      The name of the group to modify.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">username</replaceable></term>
    <listitem>
     <para>
      Users which are to be added or removed from the group. The users
      must exist.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Diagnostics</title>

  <variablelist>
   <varlistentry>
    <term><computeroutput>ALTER GROUP</computeroutput></term>
    <listitem>
     <para>
      Message returned if the alteration was successful.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>
  <para>
   Add users to a group:

<programlisting>
ALTER GROUP staff ADD USER karl, john;
</programlisting>

   Remove a user from a group:

<programlisting>
ALTER GROUP workers DROP USER beth;
</programlisting>

  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>
    
  <para>
   There is no <command>ALTER GROUP</command> statement in the SQL
   standard. The concept of roles is similar.
  </para>
 </refsect1>
</refentry>

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