psql-ref.sgml

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

          <quote>Aligned</quote> mode is the standard, human-readable,
          nicely formatted text output that is default. The
          <quote><acronym>HTML</acronym></quote> and
          <quote>LaTeX</quote> modes put out tables that are intended to
          be included in documents using the respective mark-up
          language. They are not complete documents! (This might not be
          so dramatic in <acronym>HTML</acronym>, but in LaTeX you must
          have a complete document wrapper.)
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>border</literal></term>
          <listitem>
          <para>
          The second argument must be a number. In general, the higher
          the number the more borders and lines the tables will have,
          but this depends on the particular format. In
          <acronym>HTML</acronym> mode, this will translate directly
          into the <literal>border=...</literal> attribute, in the
          others only values 0 (no border), 1 (internal dividing lines),
          and 2 (table frame) make sense.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>expanded</literal> (or <literal>x</literal>)</term>
          <listitem>
          <para>
          Toggles between regular and expanded format. When expanded
          format is enabled, query results are displayed in two
          columns, with the column name on the left and the data on
          the right. This mode is useful if the data wouldn't fit on the
          screen in the normal <quote>horizontal</quote> mode.
          </para>

          <para>
          Expanded mode is supported by all four output formats.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>null</literal></term>
          <listitem>
          <para>
          The second argument is a string that should be printed
          whenever a column is null. The default is not to print
          anything, which can easily be mistaken for, say, an empty
          string. Thus, one might choose to write <literal>\pset null
          '(null)'</literal>.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>fieldsep</literal></term>
          <listitem>
          <para>
          Specifies the field separator to be used in unaligned output
          mode. That way one can create, for example, tab- or
          comma-separated output, which other programs might prefer. To
          set a tab as field separator, type <literal>\pset fieldsep
          '\t'</literal>. The default field separator is
          <literal>'|'</literal> (a vertical bar).
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>footer</literal></term>
          <listitem>
          <para>
          Toggles the display of the default footer <literal>(x
          rows)</literal>.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>numericlocale</literal></term>
          <listitem>
          <para>
          Toggles the display of a locale-aware character to separate groups
          of digits to the left of the decimal marker.  It also enables
          a locale-aware decimal marker.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>recordsep</literal></term>
          <listitem>
          <para>
          Specifies the record (line) separator to use in unaligned
          output mode. The default is a newline character.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>tuples_only</literal> (or <literal>t</literal>)</term>
          <listitem>
          <para>
          Toggles between tuples only and full display. Full display may
          show extra information such as column headers, titles, and
          various footers. In tuples only mode, only actual table data
          is shown.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>title [ <replaceable class="parameter">text</replaceable> ]</literal></term>
          <listitem>
          <para>
          Sets the table title for any subsequently printed tables. This
          can be used to give your output descriptive tags. If no
          argument is given, the title is unset.
          </para>
          </listitem>
          </varlistentry>

          <varlistentry>
          <term><literal>tableattr</literal> (or <literal>T</literal>) <literal>[ <replaceable class="parameter">text</replaceable> ]</literal></term>
          <listitem>
          <para>
          Allows you to specify any attributes to be placed inside the
          <acronym>HTML</acronym> <sgmltag>table</sgmltag> tag. This
          could for example be <literal>cellpadding</literal> or
          <literal>bgcolor</literal>. Note that you probably don't want
          to specify <literal>border</literal> here, as that is already
          taken care of by <literal>\pset border</literal>.
          </para>
          </listitem>
          </varlistentry>


          <varlistentry>
          <term><literal>pager</literal></term>
          <listitem>
          <para>
          Controls use of a pager for query and <application>psql</>
          help output. If the environment variable <envar>PAGER</envar>
          is set, the output is piped to the specified program.
          Otherwise a platform-dependent default (such as
          <filename>more</filename>) is used.
          </para>

          <para>
          When the pager is off, the pager is not used. When the pager
          is on, the pager is used only when appropriate, i.e. the
          output is to a terminal and will not fit on the screen.
          (<application>psql</> does not do a perfect job of estimating
          when to use the pager.) <literal>\pset pager</> turns the
          pager on and off. Pager can also be set to <literal>always</>,
          which causes the pager to be always used.
          </para>
          </listitem>
          </varlistentry>
        </variablelist>
        </para>

        <para>
        Illustrations on how these different formats look can be seen in
        the <xref linkend="APP-PSQL-examples"
        endterm="APP-PSQL-examples-title"> section.
        </para>

        <tip>
        <para>
        There are various shortcut commands for <command>\pset</command>. See
        <command>\a</command>, <command>\C</command>, <command>\H</command>,
        <command>\t</command>, <command>\T</command>, and <command>\x</command>.
        </para>
        </tip>

        <note>
        <para>
        It is an error to call <command>\pset</command> without
        arguments. In the future this call might show the current status
        of all printing options.
        </para>
        </note>

        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\q</literal></term>
        <listitem>
        <para>
        Quits the <application>psql</application> program.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\qecho <replaceable class="parameter">text</replaceable> [ ... ] </literal></term>
        <listitem>
        <para>
        This command is identical to <command>\echo</command> except
        that the output will be written to the query output channel, as
        set by <command>\o</command>.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\r</literal></term>
        <listitem>
        <para>
        Resets (clears) the query buffer.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\s [ <replaceable class="parameter">filename</replaceable> ]</literal></term>
        <listitem>
        <para>
        Print or save the command line history to <replaceable
        class="parameter">filename</replaceable>. If <replaceable
        class="parameter">filename</replaceable> is omitted, the history
        is written to the standard output. This option is only available
        if <application>psql</application> is configured to use the
        <acronym>GNU</acronym> <application>Readline</application> library.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\set [ <replaceable class="parameter">name</replaceable> [ <replaceable class="parameter">value</replaceable> [ ... ] ] ]</literal></term>

        <listitem>
        <para>
        Sets the internal variable <replaceable
        class="parameter">name</replaceable> to <replaceable
        class="parameter">value</replaceable> or, if more than one value
        is given, to the concatenation of all of them. If no second
        argument is given, the variable is just set with no value. To
        unset a variable, use the <command>\unset</command> command.
        </para>

        <para>
        Valid variable names can contain characters, digits, and
        underscores. See the section <xref
        linkend="APP-PSQL-variables"
        endterm="APP-PSQL-variables-title"> below for details.
        Variable names are case-sensitive.
        </para>

        <para>
        Although you are welcome to set any variable to anything you
        want, <application>psql</application> treats several variables
        as special. They are documented in the section about variables.
        </para>

        <note>
        <para>
        This command is totally separate from the <acronym>SQL</acronym>
        command <xref linkend="SQL-SET" endterm="SQL-SET-title">.
        </para>
        </note>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\t</literal></term>
        <listitem>
        <para>
        Toggles the display of output column name headings and row count
        footer. This command is equivalent to <literal>\pset
        tuples_only</literal> and is provided for convenience.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\T <replaceable class="parameter">table_options</replaceable></literal></term>
        <listitem>
        <para>
        Allows you to specify attributes to be placed within the
        <sgmltag>table</sgmltag> tag in <acronym>HTML</acronym> tabular
        output mode. This command is equivalent to <literal>\pset
        tableattr <replaceable
        class="parameter">table_options</replaceable></literal>.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
       <term><literal>\timing</literal></term>
        <listitem>
        <para>
         Toggles a display of how long each SQL statement takes, in milliseconds.
        </para>
       </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\w</literal> {<replaceable class="parameter">filename</replaceable> | <replaceable class="parameter">|command</replaceable>}</term>
        <listitem>
        <para>
        Outputs the current query buffer to the file <replaceable
        class="parameter">filename</replaceable> or pipes it to the Unix
        command <replaceable class="parameter">command</replaceable>.
        </para>
        </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\x</literal></term>
        <listitem>
        <para>
        Toggles expanded table formatting mode. As such it is equivalent to
        <literal>\pset expanded</literal>.
       </para>
       </listitem>
      </varlistentry>


      <varlistentry>
        <term><literal>\z [ <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 a <replaceable class="parameter">pattern</replaceable> is
        specified, only tables,views and sequences whose names match the pattern are listed.
        </para>

        <para>
        The commands <command>GRANT</command> and
        <command>REVOKE</command> are used to set access privileges.
        See <xref linkend="sql-grant" endterm="sql-grant-title"> for
        more information.
        </para>