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$Header: /cvsroot/pgsql/doc/src/sgml/ref/revoke.sgml,v 1.25 2003/01/23 23:38:53 petere Exp $
PostgreSQL documentation
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<refentry id="SQL-REVOKE">
 <refmeta>
  <refentrytitle id="sql-revoke-title">REVOKE</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>REVOKE</refname>
  <refpurpose>remove access privileges</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
REVOKE [ GRANT OPTION FOR ]
    { { SELECT | INSERT | UPDATE | DELETE | RULE | REFERENCES | TRIGGER }
    [,...] | ALL [ PRIVILEGES ] }
    ON [ TABLE ] <replaceable class="PARAMETER">tablename</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | TEMPORARY | TEMP } [,...] | ALL [ PRIVILEGES ] }
    ON DATABASE <replaceable>dbname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { EXECUTE | ALL [ PRIVILEGES ] }
    ON FUNCTION <replaceable>funcname</replaceable> ([<replaceable>type</replaceable>, ...]) [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { USAGE | ALL [ PRIVILEGES ] }
    ON LANGUAGE <replaceable>langname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
    ON SCHEMA <replaceable>schemaname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1 id="SQL-REVOKE-description">
  <title>Description</title>

  <para>
   <command>REVOKE</command> allows the creator of an object to revoke
   previously granted permissions from one or more users or groups of users.
   The key word <literal>PUBLIC</literal> refers to the implicitly defined
   group of all users.
  </para>

  <para>
   Note that any particular user will have the sum
   of privileges granted directly to him, privileges granted to any group he
   is presently a member of, and privileges granted to
   <literal>PUBLIC</literal>.  Thus, for example, revoking SELECT privilege
   from <literal>PUBLIC</literal> does not necessarily mean that all users
   have lost SELECT privilege on the object: those who have it granted
   directly or via a group will still have it.
  </para>

  <para>
   See the description of the <xref linkend="sql-grant" endterm="sql-grant-title"> command for
   the meaning of the privilege types.
  </para>

  <para>
   If <literal>GRANT OPTION FOR</literal> is specified, only the grant
   option for the privilege is revoked, not the privilege itself.
  </para>

  <para>
   If a user holds a privilege with grant option and has granted it to
   other users then the privileges held by those other users are
   called dependent privileges. If the privilege or the grant option
   held by the first user is being revoked and dependent privileges
   exist, those dependent privileges are also revoked if
   <literal>CASCADE</literal> is specified, else the revoke action
   will fail.  This recursive revocation only affects privileges that
   were granted through a chain of users that is traceable to the user
   that is the subject of this <literal>REVOKE</literal> command.
   Thus, the affected users may effectively keep the privilege if it
   was also granted through other users.
  </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-notes">
  <title>Notes</title>

  <para>
   Use <xref linkend="app-psql">'s <command>\z</command> command to
   display the privileges granted on existing objects.  See also <xref
   linkend="sql-grant" endterm="sql-grant-title"> for information about the format.
  </para>

  <para>
   A user can only revoke privileges that were granted directly by
   that user.  If, for example, user A has granted a privilege with
   grant option to user B, and user B has in turned granted it to user
   C, then user A cannot revoke the privilege directly from C.
   Instead, user A could revoke the grant option from user B and use
   the <literal>CASCADE</literal> option so that the privilege is
   automatically revoked from user C.
  </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-examples">
  <title>Examples</title>

  <para>
   Revoke insert privilege for the public on table
   <literal>films</literal>:

<programlisting>
REVOKE INSERT ON films FROM PUBLIC;
</programlisting>
  </para>

  <para>
   Revoke all privileges from user <literal>manuel</literal> on view <literal>kinds</literal>:

<programlisting>  
REVOKE ALL PRIVILEGES ON kinds FROM manuel;
</programlisting>
  </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-compatibility">
  <title>Compatibility</title>

  <refsect2>
   <title>SQL92</title>

   <para>
    The compatibility notes of the <xref linkend="sql-grant" endterm="sql-grant-title"> command
    apply analogously to <command>REVOKE</command>.  The syntax summary is:

<synopsis>
REVOKE [ GRANT OPTION FOR ] { SELECT | INSERT | UPDATE | DELETE | REFERENCES }
    ON <replaceable class="parameter">object</replaceable> [ ( <replaceable class="parameter">column</replaceable> [, ...] ) ]
    FROM { PUBLIC | <replaceable class="parameter">username</replaceable> [, ...] }
    { RESTRICT | CASCADE }
</synopsis>
    One of <literal>RESTRICT</literal> or <literal>CASCADE</literal>
    is required.
   </para>
  </refsect2>
 </refsect1>

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

  <simpara>
   <xref linkend="sql-grant" endterm="sql-grant-title">
  </simpara>
 </refsect1>

</refentry>

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