psql-ref.sgml

postgresql8.3.4源码,开源数据库

        <term><literal>\dFp+ [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
         Lists available text search parsers.
         If <replaceable class="parameter">pattern</replaceable> is specified,
         only parsers whose names match the pattern are shown.
         If the form <literal>\dFp+</literal> is used, a full description of
         each parser is shown, including the underlying functions and the
         list of recognized token types.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\dFt [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <term><literal>\dFt+ [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
         Lists available text search templates.
         If <replaceable class="parameter">pattern</replaceable> is specified,
         only templates whose names match the pattern are shown.
         If the form <literal>\dFt+</literal> is used, additional information
         is shown about each template, including the underlying function names.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dg [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists all database roles. If <replaceable
        class="parameter">pattern</replaceable> is specified, only
        those roles whose names match the pattern are listed.
        (This command is now effectively the same as <literal>\du</>.)
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\distvS [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>

        <listitem>
        <para>
        This is not the actual command name: the letters
        <literal>i</literal>, <literal>s</literal>,
        <literal>t</literal>, <literal>v</literal>,
        <literal>S</literal> stand for index, sequence, table, view,
        and system table, respectively. You can specify any or all of
        these letters, in any order, to obtain a listing of all the
        matching objects.  The letter <literal>S</literal> restricts
        the listing to system objects; without <literal>S</literal>,
        only non-system objects are shown.  If <literal>+</literal> is
        appended to the command name, each object is listed with its
        associated description, if any.
        </para>

        <para>
        If <replaceable class="parameter">pattern</replaceable> is
        specified, only objects whose names match the pattern are listed.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dl</literal></term>
        <listitem>
        <para>
        This is an alias for <command>\lo_list</command>, which shows a
        list of large objects.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dn [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <term><literal>\dn+ [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>

        <listitem>
        <para>
        Lists all available schemas (namespaces). If <replaceable
        class="parameter">pattern</replaceable> (a regular expression)
        is specified, only schemas whose names match the pattern are listed.
        Non-local temporary schemas are suppressed.  If <literal>+</literal>
        is appended to the command name, each object is listed with its associated
        permissions and description, if any.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\do [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists available operators with their operand and return types.
        If <replaceable class="parameter">pattern</replaceable> is
        specified, only operators whose names match the pattern are listed.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dp [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Produces a list of all available tables, views and sequences with their
        associated access privileges.
        If <replaceable class="parameter">pattern</replaceable> is
        specified, only tables, views and sequences whose names match the pattern are listed.
        </para>

        <para>
        The <xref linkend="sql-grant" endterm="sql-grant-title"> and
        <xref linkend="sql-revoke" endterm="sql-revoke-title">
        commands are used to set access privileges.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dT [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <term><literal>\dT+ [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists all data types or only those that match <replaceable
        class="parameter">pattern</replaceable>. The command form
        <literal>\dT+</literal> shows extra information.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\du [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists all database roles, or only those that match <replaceable
        class="parameter">pattern</replaceable>.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\edit</literal> (or <literal>\e</literal>) <literal>[ <replaceable class="parameter">filename</replaceable> ]</literal></term>

        <listitem>
        <para>
        If <replaceable class="parameter">filename</replaceable> is
        specified, the file is edited; after the editor exits, its
        content is copied back to the query buffer. If no argument is
        given, the current query buffer is copied to a temporary file
        which is then edited in the same fashion.
        </para>

        <para>
        The new query buffer is then re-parsed according to the normal
        rules of <application>psql</application>, where the whole buffer
        is treated as a single line. (Thus you cannot make scripts this
        way. Use <command>\i</command> for that.) This means also that
        if the query ends with (or rather contains) a semicolon, it is
        immediately executed. In other cases it will merely wait in the
        query buffer.
        </para>

        <tip>
        <para>
        <application>psql</application> searches the environment
        variables <envar>PSQL_EDITOR</envar>, <envar>EDITOR</envar>, and
        <envar>VISUAL</envar> (in that order) for an editor to use. If
        all of them are unset, <filename>vi</filename> is used on Unix
        systems, <filename>notepad.exe</filename> on Windows systems.
        </para>
        </tip>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\echo <replaceable class="parameter">text</replaceable> [ ... ]</literal></term>
        <listitem>
        <para>
        Prints the arguments to the standard output, separated by one
        space and followed by a newline. This can be useful to
        intersperse information in the output of scripts. For example:
<programlisting>
=&gt; <userinput>\echo `date`</userinput>
Tue Oct 26 21:40:57 CEST 1999
</programlisting>
        If the first argument is an unquoted <literal>-n</literal> the trailing
        newline is not written.
        </para>

        <tip>
        <para>
        If you use the <command>\o</command> command to redirect your
        query output you might wish to use <command>\qecho</command>
        instead of this command.
        </para>
        </tip>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\encoding [ <replaceable class="parameter">encoding</replaceable> ]</literal></term>

        <listitem>
        <para>
        Sets the client character set encoding.  Without an argument, this command
        shows the current encoding.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\f [ <replaceable class="parameter">string</replaceable> ]</literal></term>

        <listitem>
        <para>
        Sets the field separator for unaligned query output. The default
        is the vertical bar (<literal>|</literal>). See also
        <command>\pset</command> for a generic way of setting output
        options.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\g</literal> [ { <replaceable class="parameter">filename</replaceable> | <literal>|</literal><replaceable class="parameter">command</replaceable> } ]</term>

        <listitem>
        <para>
        Sends the current query input buffer to the server and
        optionally stores the query's output in <replaceable
        class="parameter">filename</replaceable> or pipes the output
        into a separate Unix shell executing <replaceable
        class="parameter">command</replaceable>. A bare
        <literal>\g</literal> is virtually equivalent to a semicolon. A
        <literal>\g</literal> with argument is a <quote>one-shot</quote>
        alternative to the <command>\o</command> command.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\help</literal> (or <literal>\h</literal>) <literal>[ <replaceable class="parameter">command</replaceable> ]</literal></term>
        <listitem>
        <para>
        Gives syntax help on the specified <acronym>SQL</acronym>
        command. If <replaceable class="parameter">command</replaceable>
        is not specified, then <application>psql</application> will list
        all the commands for which syntax help is available. If
        <replaceable class="parameter">command</replaceable> is an
        asterisk (<literal>*</literal>), then syntax help on all
        <acronym>SQL</acronym> commands is shown.
        </para>

        <note>
        <para>
        To simplify typing, commands that consists of several words do
        not have to be quoted. Thus it is fine to type <userinput>\help
        alter table</userinput>.
        </para>
        </note>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\H</literal></term>
        <listitem>
        <para>
        Turns on <acronym>HTML</acronym> query output format. If the
        <acronym>HTML</acronym> format is already on, it is switched
        back to the default aligned text format. This command is for
        compatibility and convenience, but see <command>\pset</command>
        about setting other output options.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\i <replaceable class="parameter">filename</replaceable></literal></term>
        <listitem>
        <para>
        Reads input from the file <replaceable
        class="parameter">filename</replaceable> and executes it as
        though it had been typed on the keyboard.
        </para>
        <note>
        <para>
        If you want to see the lines on the screen as they are read you
        must set the variable <varname>ECHO</varname> to
        <literal>all</literal>.
        </para>
        </note>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\l</literal> (or <literal>\list</literal>)</term>
        <term><literal>\l+</literal> (or <literal>\list+</literal>)</term>
        <listitem>
        <para>
        List the names, owners, and character set encodings of all the databases in
        the server. If <literal>+</literal> is appended to the command
        name, database descriptions are also displayed.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\lo_export <replaceable class="parameter">loid</replaceable> <replaceable class="parameter">filename</replaceable></literal></term>

        <listitem>
        <para>
        Reads the large object with <acronym>OID</acronym> <replaceable
        class="parameter">loid</replaceable> from the database and
        writes it to <replaceable
        class="parameter">filename</replaceable>. Note that this is
        subtly different from the server function
        <function>lo_export</function>, which acts with the permissions
        of the user that the database server runs as and on the server's
        file system.
        </para>