dropdb.sgml

来自「postgresql8.3.4源码,开源数据库」· SGML 代码 · 共 233 行

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$PostgreSQL: pgsql/doc/src/sgml/ref/dropdb.sgml,v 1.34 2007/12/11 19:57:32 tgl Exp $
PostgreSQL documentation
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<refentry id="APP-DROPDB">
 <refmeta>
  <refentrytitle id="APP-DROPDB-TITLE"><application>dropdb</application></refentrytitle>
  <manvolnum>1</manvolnum>
  <refmiscinfo>Application</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>dropdb</refname>
  <refpurpose>remove a <productname>PostgreSQL</productname> database</refpurpose>
 </refnamediv>

 <indexterm zone="app-dropdb">
  <primary>dropdb</primary>
 </indexterm>

 <refsynopsisdiv>
  <cmdsynopsis>
   <command>dropdb</command>
   <arg rep="repeat"><replaceable>option</replaceable></arg>
   <arg choice="plain"><replaceable>dbname</replaceable></arg>
  </cmdsynopsis>
 </refsynopsisdiv>


 <refsect1>
  <title>Description</title>

  <para>
   <application>dropdb</application> destroys an existing
   <productname>PostgreSQL</productname> database.
   The user who executes this command must be a database
   superuser or the owner of the database.
  </para>

  <para>
   <application>dropdb</application> is a wrapper around the
   <acronym>SQL</acronym> command <xref linkend="SQL-DROPDATABASE"
   endterm="SQL-DROPDATABASE-title">.
   There is no effective difference between dropping databases via
   this utility and via other methods for accessing the server.
  </para>

 </refsect1>


 <refsect1>
  <title>Options</title>

  <para>
   <application>dropdb</> accepts the following command-line arguments:

    <variablelist>
     <varlistentry>
      <term><replaceable class="parameter">dbname</replaceable></term>
      <listitem>
       <para>
        Specifies the name of the database to be removed.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-e</></term>
      <term><option>--echo</></term>
      <listitem>
       <para>
        Echo the commands that <application>dropdb</application> generates
        and sends to the server.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-i</></term>
      <term><option>--interactive</></term>
      <listitem>
       <para>
       Issues a verification prompt before doing anything destructive.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
  </para>

  <para>
   <application>dropdb</application> also accepts the following
   command-line arguments for connection parameters:

   <variablelist>
     <varlistentry>
      <term><option>-h <replaceable class="parameter">host</replaceable></></term>
      <term><option>--host <replaceable class="parameter">host</replaceable></></term>
      <listitem>
       <para>
        Specifies the host name of the machine on which the 
        server
        is running.  If the value begins with a slash, it is used 
        as the directory for the Unix domain socket.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-p <replaceable class="parameter">port</replaceable></></term>
      <term><option>--port <replaceable class="parameter">port</replaceable></></term>
      <listitem>
       <para>
        Specifies the TCP port or local Unix domain socket file 
        extension on which the server
        is listening for connections.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-U <replaceable class="parameter">username</replaceable></></term>
      <term><option>--username <replaceable class="parameter">username</replaceable></></term>
      <listitem>
       <para>
        User name to connect as.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-W</></term>
      <term><option>--password</></term>
      <listitem>
       <para>
        Force <application>dropdb</application> to prompt for a
        password before connecting to a database.  
       </para>

       <para>
        This option is never essential, since
        <application>dropdb</application> will automatically prompt
        for a password if the server demands password authentication.
        However, <application>dropdb</application> will waste a
        connection attempt finding out that the server wants a password.
        In some cases it is worth typing <option>-W</> to avoid the extra
        connection attempt.
       </para>
      </listitem>
     </varlistentry>
   </variablelist>
  </para>
 </refsect1>


 <refsect1>
  <title>Environment</title>

  <variablelist>
   <varlistentry>
    <term><envar>PGHOST</envar></term>
    <term><envar>PGPORT</envar></term>
    <term><envar>PGUSER</envar></term>

    <listitem>
     <para>
      Default connection parameters
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   This utility, like most other <productname>PostgreSQL</> utilities,
   also uses the environment variables supported by <application>libpq</>
   (see <xref linkend="libpq-envars">).
  </para>

 </refsect1>


 <refsect1>
  <title>Diagnostics</title>

  <para>
   In case of difficulty, see <xref linkend="SQL-DROPDATABASE"
   endterm="sql-dropdatabase-title"> and <xref linkend="APP-PSQL"> for
   discussions of potential problems and error messages.
   The database server must be running at the
   targeted host.  Also, any default connection settings and environment
   variables used by the <application>libpq</application> front-end
   library will apply.
  </para>

 </refsect1>


 <refsect1>
  <title>Examples</title>

   <para>
    To destroy the database <literal>demo</literal> on the default
    database server:
<screen>
<prompt>$ </prompt><userinput>dropdb demo</userinput>
</screen>
   </para>

   <para>
    To destroy the database <literal>demo</literal> using the
    server on host <literal>eden</literal>, port 5000, with verification and a peek
    at the underlying command:
<screen>
<prompt>$ </prompt><userinput>dropdb -p 5000 -h eden -i -e demo</userinput>
<computeroutput>Database "demo" will be permanently deleted.
Are you sure? (y/n) </computeroutput><userinput>y</userinput>
<computeroutput>DROP DATABASE demo;</computeroutput>
</screen>
   </para>
 </refsect1>


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

  <simplelist type="inline">
   <member><xref linkend="app-createdb"></member>
   <member><xref linkend="sql-dropdatabase" endterm="sql-dropdatabase-title"></member>
  </simplelist>
 </refsect1>

</refentry>