alter_group.sgml

postgresql8.3.4源码,开源数据库

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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>change role name or membership</refpurpose>
 </refnamediv>

 <indexterm zone="sql-altergroup">
  <primary>ALTER GROUP</primary>
 </indexterm>

 <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> [, ... ]

ALTER GROUP <replaceable class="PARAMETER">groupname</replaceable> RENAME TO <replaceable>newname</replaceable>
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER GROUP</command> changes the attributes of a user group.
   This is an obsolete command, though still accepted for backwards
   compatibility, because groups (and users too) have been superseded by the
   more general concept of roles.
  </para>

  <para>
   The first two variants add users to a group or remove them from a group.
   (Any role can play the part of either a <quote>user</> or a
   <quote>group</> for this purpose.)  These variants are effectively
   equivalent to granting or revoking membership in the role named as the
   <quote>group</>; so the preferred way to do this is to use
   <xref linkend="SQL-GRANT" endterm="SQL-GRANT-title"> or
   <xref linkend="SQL-REVOKE" endterm="SQL-REVOKE-title">.
  </para>

  <para>
   The third variant changes the name of the group.  This is exactly
   equivalent to renaming the role with 
   <xref linkend="sql-alterrole" endterm="sql-alterrole-title">.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

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

   <varlistentry>
    <term><replaceable class="PARAMETER">username</replaceable></term>
    <listitem>
     <para>
      Users (roles) that are to be added to or removed from the group.
      The users must already exist; <command>ALTER GROUP</> does not
      create or drop users.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable>newname</replaceable></term>
    <listitem>
     <para>
      The new name of the group.
     </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.
  </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-grant" endterm="sql-grant-title"></member>
   <member><xref linkend="sql-revoke" endterm="sql-revoke-title"></member>
   <member><xref linkend="sql-alterrole" endterm="sql-alterrole-title"></member>
  </simplelist>
 </refsect1>

</refentry>