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<chapter id="plpgsql">

</indexterm>

<para>

With the <literal>LOOP</>, <literal>EXIT</>, <literal>WHILE</>,

and<literal>FOR</> statements, you can arrange for your

<application>PL/pgSQL</application> function to repeat a series

of commands.

With the <literal>LOOP</>, <literal>EXIT</>,

<literal>CONTINUE</>, <literal>WHILE</>, and <literal>FOR</>

statements, you can arrange for your<application>PL/pgSQL</>

function to repeat a seriesof commands.

</para>

<sect3>

<sect3>

<title><literal>EXIT</></title>

<indexterm>

<primary>EXIT</primary>

<secondary>in PL/pgSQL</secondary>

</indexterm>

<synopsis>

EXIT <optional> <replaceable>label</replaceable> </optional> <optional> WHEN <replaceable>expression</replaceable> </optional>;

</synopsis>

<para>

If no <replaceable>label</replaceable> is given,

the innermost loop is terminated and the

statement following <literal>END LOOP</> 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</>.

If no <replaceable>label</replaceable> is given, the innermost

loop is terminated and the statement following <literal>END

LOOP</> 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</>.

</para>

<para>

If <literal>WHEN</> ispresent,loop exit occurs only if the specified

condition is true, otherwisecontrol passes to the statement after

<literal>EXIT</>.

If <literal>WHEN</> isspecified, theloop exit occurs only if

<replaceable>expression</> is true. Otherwise,control passes

to the statement after<literal>EXIT</>.

</para>

<para>

<literal>EXIT</> can be used to cause early exit from all types of

loops; it is not limited to use with unconditional loops.

<literal>EXIT</> can be used with all types of loops; it is

not limited to use with unconditional loops. When used with a

<literal>BEGIN</literal> block, <literal>EXIT</literal> passes

control to the next statement after the end of the block.

</para>

<para>

</para>

</sect3>

<sect3>

<title><literal>CONTINUE</></title>

<indexterm>

<primary>CONTINUE</primary>

<secondary>in PL/pgSQL</secondary>

</indexterm>

<synopsis>

CONTINUE <optional> <replaceable>label</replaceable> </optional> <optional> WHEN <replaceable>expression</replaceable> </optional>;

</synopsis>

<para>

If no <replaceable>label</> is given, the next iteration of

the innermost loop is begun. That is, control is passed back

to the loop control expression (if any), and the body of the

loop is re-evaluated. If <replaceable>label</> is present, it

specifies the label of the loop whose execution will be

continued.

</para>

<para>

If <literal>WHEN</> is specified, the next iteration of the

loop is begun only if <replaceable>expression</> is

true. Otherwise, control passes to the statement after

<literal>CONTINUE</>.

</para>

<para>

<literal>CONTINUE</> can be used with all types of loops; it

is not limited to use with unconditional loops.

</para>

<para>

Examples:

<programlisting>

LOOP

-- some computations

EXIT WHEN count &gt; 100;

CONTINUE WHEN count &lt; 50;

-- some computations for count IN [50 .. 100]

END LOOP;

</programlisting>

</para>

</sect3>

<sect3>

<title><literal>WHILE</></title>

<indexterm>

<primary>WHILE</primary>

<secondary>in PL/pgSQL</secondary>

</indexterm>

<synopsis>

<optional>&lt;&lt;<replaceable>label</replaceable>&gt;&gt;</optional>

WHILE <replaceable>expression</replaceable> LOOP

%union {

int32ival;

boolboolean;

char*str;

{

;

decl_const:

{$$ =0; }

{$$ =false; }

{$$ =1; }

{$$ =true; }

;

decl_datatype:

;

decl_notnull:

{$$ =0; }

{$$ =false; }

{$$ =1; }

{$$ =true; }

;

decl_defval:';'

}

;

stmt_exit:K_EXITlnoopt_exitlabelopt_exitcond

stmt_exit:exit_typelnoopt_exitlabelopt_exitcond

{

PLpgSQL_stmt_exit *new;

new = palloc0(sizeof(PLpgSQL_stmt_exit));

new->cmd_type = PLPGSQL_STMT_EXIT;

new->lineno =$2;

new->is_exit =$1;

new->lineno =$2;

new->label =$3;

new->cond =$4;

$$ = (PLpgSQL_stmt *)new;

}

;

exit_type:K_EXIT

{

$$ =true;

}

{

$$ =false;

}

;

stmt_return:K_RETURNlno

{

PLpgSQL_stmt_return *new;

new = palloc0(sizeof(PLpgSQL_stmt_return));

new->cmd_type = PLPGSQL_STMT_RETURN;

new->lineno =$2;

new->expr =NULL;

new->retvarno= -1;

new->expr =NULL;

new->retvarno= -1;

if (plpgsql_curr_compile->fn_retset)

{