drop_schema.sgml

postgresql8.3.4源码,开源数据库

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$PostgreSQL: pgsql/doc/src/sgml/ref/drop_schema.sgml,v 1.8 2006/09/16 00:30:18 momjian Exp $
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<refentry id="SQL-DROPSCHEMA">
 <refmeta>
  <refentrytitle id="SQL-DROPSCHEMA-TITLE">DROP SCHEMA</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>DROP SCHEMA</refname>
  <refpurpose>remove a schema</refpurpose>
 </refnamediv>

 <indexterm zone="sql-dropschema">
  <primary>DROP SCHEMA</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
DROP SCHEMA [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>DROP SCHEMA</command> removes schemas from the database.
  </para>

  <para>
   A schema can only be dropped by its owner or a superuser.  Note that
   the owner can drop the schema (and thereby all contained objects)
   even if he does not own some of the objects within the schema.
  </para>
 </refsect1>
  
 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><literal>IF EXISTS</literal></term>
    <listitem>
     <para>
      Do not throw an error if the schema does not exist. A notice is issued 
      in this case.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">name</replaceable></term>
    <listitem>
     <para>
      The name of a schema.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>CASCADE</literal></term>
    <listitem>
     <para>
      Automatically drop objects (tables, functions, etc.) that are
      contained in the schema.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>RESTRICT</literal></term>
    <listitem>
     <para>
      Refuse to drop the schema if it contains any objects.  This is
      the default.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   To remove schema <literal>mystuff</literal> from the database,
   along with everything it contains:

<programlisting>
DROP SCHEMA mystuff CASCADE;
</programlisting>
  </para>
 </refsect1>
 
 <refsect1>
  <title>Compatibility</title>
  
  <para>
   <command>DROP SCHEMA</command> is fully conforming with the SQL
   standard, except that the standard only allows one schema to be
   dropped per command, and apart from the 
   <literal>IF EXISTS</> option, which is a <productname>PostgreSQL</> 
   extension.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-alterschema" endterm="sql-alterschema-title"></member>
   <member><xref linkend="sql-createschema" endterm="sql-createschema-title"></member>
  </simplelist>
 </refsect1>

</refentry>