be used to exit the function
      early; but do not write an expression following
      <command>RETURN</command>.
     </para>

     <para>
      The return value of a function cannot be left undefined. If
      control reaches the end of the top-level block of the function
      without hitting a <command>RETURN</command> statement, a run-time
      error will occur.  This restriction does not apply to functions
      with output parameters and functions returning <type>void</type>,
      however.  In those cases a <command>RETURN</command> statement is
      automatically executed if the top-level block finishes.
     </para>

     <para>
      Some examples:

<programlisting>
-- functions returning a scalar type
RETURN 1 + 2;
RETURN scalar_var;

-- functions returning a composite type
RETURN composite_type_var;
RETURN (1, 2, 'three'::text);  -- must cast columns to correct types
</programlisting>
     </para>
    </sect3>

    <sect3 id="plpgsql-statements-returning-return-next">
     <title><command>RETURN NEXT</command> and <command>RETURN QUERY</command></title>
    <indexterm>
     <primary>RETURN NEXT</primary>
     <secondary>in PL/pgSQL</secondary>
    </indexterm>
    <indexterm>
     <primary>RETURN QUERY</primary>
     <secondary>in PL/pgSQL</secondary>
    </indexterm>

<synopsis>
RETURN NEXT <replaceable>expression</replaceable>;
RETURN QUERY <replaceable>query</replaceable>;
RETURN QUERY EXECUTE <replaceable class="command">command-string</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ... </optional> </optional>;
</synopsis>

     <para>
      When a <application>PL/pgSQL</application> function is declared to return
      <literal>SETOF <replaceable>sometype</replaceable></literal>, the procedure
      to follow is slightly different.  In that case, the individual
      items to return are specified by a sequence of <command>RETURN
      NEXT</command> or <command>RETURN QUERY</command> commands, and
      then a final <command>RETURN</command> command with no argument
      is used to indicate that the function has finished executing.
      <command>RETURN NEXT</command> can be used with both scalar and
      composite data types; with a composite result type, an entire
      <quote>table</quote> of results will be returned.
      <command>RETURN QUERY</command> appends the results of executing
      a query to the function's result set. <command>RETURN
      NEXT</command> and <command>RETURN QUERY</command> can be freely
      intermixed in a single set-returning function, in which case
      their results will be concatenated.
     </para>

     <para>
      <command>RETURN NEXT</command> and <command>RETURN
      QUERY</command> do not actually return from the function &mdash;
      they simply append zero or more rows to the function's result
      set.  Execution then continues with the next statement in the
      <application>PL/pgSQL</application> function.  As successive
      <command>RETURN NEXT</command> or <command>RETURN
      QUERY</command> commands are executed, the result set is built
      up.  A final <command>RETURN</command>, which should have no
      argument, causes control to exit the function (or you can just
      let control reach the end of the function).
     </para>

     <para>
      <command>RETURN QUERY</command> has a variant
      <command>RETURN QUERY EXECUTE</command>, which specifies the
      query to be executed dynamically.  Parameter expressions can
      be inserted into the computed query string via <literal>USING</literal>,
      in just the same way as in the <command>EXECUTE</command> command.
     </para>

     <para>
      If you declared the function with output parameters, write just
      <command>RETURN NEXT</command> with no expression.  On each
      execution, the current values of the output parameter
      variable(s) will be saved for eventual return as a row of the
      result.  Note that you must declare the function