psql-ref.sgml

postgresql8.3.4源码,开源数据库

        <listitem>
        <para>
        If the current table output format is unaligned, it is switched to aligned.
        If it is not unaligned, it is set to unaligned. This command is
        kept for backwards compatibility. See <command>\pset</command> for a
        more general solution.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
       <term><literal>\cd [ <replaceable>directory</replaceable> ]</literal></term>
       <listitem>
        <para>
         Changes the current working directory to
         <replaceable>directory</replaceable>. Without argument, changes
         to the current user's home directory.
        </para>

        <tip>
         <para>
          To print your current working directory, use <literal>\!pwd</literal>.
         </para>
        </tip>
       </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\C [ <replaceable class="parameter">title</replaceable> ]</literal></term>
        <listitem>
        <para>
        Sets the title of any tables being printed as the result of a
        query or unset any such title. This command is equivalent to
        <literal>\pset title <replaceable
        class="parameter">title</replaceable></literal>. (The name of
        this command derives from <quote>caption</quote>, as it was
        previously only used to set the caption in an
        <acronym>HTML</acronym> table.)
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\connect</literal> (or <literal>\c</literal>) <literal>[ <replaceable class="parameter">dbname</replaceable> [ <replaceable class="parameter">username</replaceable> ] [ <replaceable class="parameter">host</replaceable> ] [ <replaceable class="parameter">port</replaceable> ] ]</literal></term>
        <listitem>
        <para>
        Establishes a new connection to a <productname>PostgreSQL</>
        server. If the new connection is successfully made, the
        previous connection is closed. If any of <replaceable
        class="parameter">dbname</replaceable>, <replaceable
        class="parameter">username</replaceable>, <replaceable
        class="parameter">host</replaceable> or <replaceable
        class="parameter">port</replaceable> are omitted or specified
        as <literal>-</literal>, the value of that parameter from the
        previous connection is used. If there is no previous
        connection, the <application>libpq</application> default for
        the parameter's value is used.
        </para>

        <para>
        If the connection attempt failed (wrong user name, access
        denied, etc.), the previous connection will only be kept if
        <application>psql</application> is in interactive mode. When
        executing a non-interactive script, processing will
        immediately stop with an error. This distinction was chosen as
        a user convenience against typos on the one hand, and a safety
        mechanism that scripts are not accidentally acting on the
        wrong database on the other hand.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\copy { <replaceable class="parameter">table</replaceable> [ ( <replaceable class="parameter">column_list</replaceable> ) ] | ( <replaceable class="parameter">query</replaceable> ) }
        { <literal>from</literal> | <literal>to</literal> }
        { <replaceable class="parameter">filename</replaceable> | stdin | stdout | pstdin | pstdout }
        [ with ]
            [ binary ]
            [ oids ]
            [ delimiter [ as ] '<replaceable class="parameter">character</replaceable>' ]
            [ null [ as ] '<replaceable class="parameter">string</replaceable>' ]
            [ csv
              [ header ]
              [ quote [ as ] '<replaceable class="parameter">character</replaceable>' ]
              [ escape [ as ] '<replaceable class="parameter">character</replaceable>' ]
              [ force quote <replaceable class="parameter">column_list</replaceable> ]
              [ force not null <replaceable class="parameter">column_list</replaceable> ] ]</literal>
        </term>

        <listitem>
        <para>
        Performs a frontend (client) copy. This is an operation that
        runs an <acronym>SQL</acronym> <xref linkend="SQL-COPY"
        endterm="SQL-COPY-title"> command, but instead of the server
        reading or writing the specified file,
        <application>psql</application> reads or writes the file and
        routes the data between the server and the local file system.
        This means that file accessibility and privileges are those of
        the local user, not the server, and no SQL superuser
        privileges are required.
        </para>

        <para>
        The syntax of the command is similar to that of the
        <acronym>SQL</acronym> <xref linkend="sql-copy"
        endterm="sql-copy-title"> command.  Note that, because of this,
        special parsing rules apply to the <command>\copy</command>
        command. In particular, the variable substitution rules and
        backslash escapes do not apply.
        </para>

        <para>
        <literal>\copy ... from stdin | to stdout</literal>
        reads/writes based on the command input and output respectively.
        All rows are read from the same source that issued the command,
        continuing until <literal>\.</literal> is read or the stream
        reaches <acronym>EOF</>. Output is sent to the same place as
        command output. To read/write from
        <application>psql</application>'s standard input or output, use
        <literal>pstdin</> or <literal>pstdout</>. This option is useful
        for populating tables in-line within a SQL script file.
        </para>

        <tip>
        <para>
        This operation is not as efficient as the <acronym>SQL</acronym>
        <command>COPY</command> command because all data must pass
        through the client/server connection. For large
        amounts of data the <acronym>SQL</acronym> command might be preferable.
        </para>
        </tip>

        </listitem>
      </varlistentry>

      <varlistentry>
        <term><literal>\copyright</literal></term>
        <listitem>
        <para>
        Shows the copyright and distribution terms of
        <productname>PostgreSQL</productname>.
        </para>
        </listitem>
      </varlistentry>

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

        <listitem>
        <para>
        For each relation (table, view, index, or sequence) matching the
        <replaceable class="parameter">pattern</replaceable>, show all
        columns, their types, the tablespace (if not the default) and any special
        attributes such as <literal>NOT NULL</literal> or defaults, if
        any. Associated indexes, constraints, rules, and triggers are
        also shown, as is the view definition if the relation is a view.
        (<quote>Matching the pattern</> is defined below.)
        </para>

        <para>
        The command form <literal>\d+</literal> is identical, except that
        more information is displayed: any comments associated with the
        columns of the table are shown, as is the presence of OIDs in the
        table.
        </para>

        <note>
        <para>
        If <command>\d</command> is used without a
        <replaceable class="parameter">pattern</replaceable> argument, it is
        equivalent to <command>\dtvs</command> which will show a list of
        all tables, views, and sequences. This is purely a convenience
        measure.
        </para>
        </note>
        </listitem>
      </varlistentry>

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

        <listitem>
        <para>
        Lists all available aggregate functions, together with their
        return type and the data types they operate on. If <replaceable
        class="parameter">pattern</replaceable>
        is specified, only aggregates whose names match the pattern are shown.
        </para>
        </listitem>
      </varlistentry>


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

        <listitem>
        <para>
        Lists all available tablespaces. If <replaceable
        class="parameter">pattern</replaceable>
        is specified, only tablespaces whose names match the pattern are shown.
        If <literal>+</literal> is appended to the command name, each object 
        is listed with its associated permissions.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dc [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists all available conversions between character-set encodings.
        If <replaceable class="parameter">pattern</replaceable>
        is specified, only conversions whose names match the pattern are
        listed.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dC</literal></term>
        <listitem>
        <para>
        Lists all available type casts.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dd [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Shows the descriptions of objects matching the <replaceable
        class="parameter">pattern</replaceable>, or of all visible objects if
        no argument is given.  But in either case, only objects that have
        a description are listed.
        (<quote>Object</quote> covers aggregates, functions, operators,
        types, relations (tables, views, indexes, sequences, large
        objects), rules, and triggers.) For example:
<programlisting>
=&gt; <userinput>\dd version</userinput>
                     Object descriptions
   Schema   |  Name   |  Object  |        Description
------------+---------+----------+---------------------------
 pg_catalog | version | function | PostgreSQL version string
(1 row)
</programlisting>
        </para>

        <para>
        Descriptions for objects can be created with the <xref
        linkend="sql-comment" endterm="sql-comment-title">
        <acronym>SQL</acronym> command.
       </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\dD [ <replaceable class="parameter">pattern</replaceable> ]</literal></term>
        <listitem>
        <para>
        Lists all available domains. If <replaceable
        class="parameter">pattern</replaceable>
        is specified, only matching domains are shown.
        </para>
        </listitem>
      </varlistentry>


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

        <listitem>
        <para>
        Lists available functions, together with their argument and
        return types. If <replaceable
        class="parameter">pattern</replaceable>
        is specified, only functions whose names match the pattern are shown.
        If the form <literal>\df+</literal> is used, additional information about
        each function, including volatility, language, source code and description, is shown.
        </para>

        <note>
        <para>
        To look up functions taking argument or returning values of a specific
        type, use your pager's search capability to scroll through the <literal>\df</>
        output.
        </para>

        <para>
        To reduce clutter, <literal>\df</> does not show data type I/O
        functions.  This is implemented by ignoring functions that accept
        or return type <type>cstring</>.
        </para>
        </note>

        </listitem>
      </varlistentry>


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

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

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