</synopsis>

     <para>
      <literal>LOOP</literal> defines an unconditional loop that is repeated
      indefinitely until terminated by an <literal>EXIT</literal> or
      <command>RETURN</command> statement.  The optional
      <replaceable>label</replaceable> can be used by <literal>EXIT</literal>
      and <literal>CONTINUE</literal> statements within nested loops to
      specify which loop those statements refer to.
     </para>
    </sect3>

     <sect3 id="plpgsql-control-structures-loops-exit">
      <title><literal>EXIT</literal></title>

     <indexterm>
      <primary>EXIT</primary>
      <secondary>in PL/pgSQL</secondary>
     </indexterm>

<synopsis>
EXIT <optional> <replaceable>label</replaceable> </optional> <optional> WHEN <replaceable>boolean-expression</replaceable> </optional>;
</synopsis>

       <para>
        If no <replaceable>label</replaceable> is given, the innermost
        loop is terminated and the statement following <literal>END
        LOOP</literal> is executed next.  If <replaceable>label</replaceable>
        is given, it must be the label of the current or some outer
        level of nested loop or block. Then the named loop or block is
        terminated and control continues with the statement after the
        loop's/block's corresponding <literal>END</literal>.
       </para>

       <para>
        If <literal>WHEN</literal> is specified, the loop exit occurs only if
        <replaceable>boolean-expression</replaceable> is true. Otherwise, control passes
        to the statement after <literal>EXIT</literal>.
       </para>

       <para>
        <literal>EXIT</literal> can be used with all types of loops; it is
        not limited to use with unconditional loops.
       </para>

       <para>
        When used with a
        <literal>BEGIN</literal> block, <literal>EXIT</literal> passes
        control to the next statement after the end of the block.
        Note that a label must be used for this purpose; an unlabeled
        <literal>EXIT</literal> is never considered to match a
        <literal>BEGIN</literal> block.  (This is a change from
        pre-8.4 releases of <productname>PostgreSQL</productname>, which
        would allow an unlabeled <literal>EXIT</literal> to match
        a <literal>BEGIN</literal> block.)
       </para>

       <para>
        Examples:
<programlisting>
LOOP
    -- some computations
    IF count &gt; 0 THEN
        EXIT;  -- exit loop
    END IF;
END LOOP;

LOOP
    -- some computations
    EXIT WHEN count &gt; 0;  -- same result as previous example
END LOOP;

&lt;&lt;ablock&gt;&gt;
BEGIN
    -- some computations
    IF stocks &gt; 100000 THEN
        EXIT ablock;  -- causes exit from the BEGIN block
    END IF;
    -- computations here will be skipped when stocks &gt; 100000
END;
</programlisting>
       </para>
     </sect3>

     <sect3 id="plpgsql-control-structures-loops-continue">
      <title><literal>CONTINUE</literal></title>

     <indexterm>
      <primary>CONTINUE</primary>
      <secondary>in PL/pgSQL</secondary>
     </indexterm>

<synopsis>
CONTINUE <optional> <replaceable>label</replaceable> </optional> <optional> WHEN <replaceable>boolean-expression</replaceable> </optional>;
</synopsis>

       <para>
        If no <replaceable>label</replaceable> is given, the next iteration of
        the innermost loop is begun. That is, all statements remaining
        in the loop body are skipped, and control returns
        to the loop control expression (if any) to determine whether
        another loop iteration is needed.
        If <replaceable>label</replaceable> is present, it
        specifies the label of the loop whose execution will be
        continued.
       </para>

       <para>
        If <literal>WHEN</literal> is specified, the next iteration of the
        loop is begun only if <replaceable>boolean-expression</replaceable> is
        true. Otherwise, control passes to the statement after
        <literal>CONTINUE</literal>.