<!--
-$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.74 2005/06/22 01:35:02 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.75 2005/07/02 08:59:47 neilc Exp $
-->
<chapter id="plpgsql">
<replaceable>declarations</replaceable> </optional>
BEGIN
<replaceable>statements</replaceable>
-END;
+END <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
</para>
<title><literal>LOOP</></title>
<synopsis>
-<optional><<<replaceable>label</replaceable>>></optional>
+<optional> <<<replaceable>label</replaceable>>> </optional>
LOOP
<replaceable>statements</replaceable>
-END LOOP;
+END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
<para>
- <literal>LOOP</> defines an unconditional loop that is repeated indefinitely
- until terminated by an <literal>EXIT</> or <command>RETURN</command>
- statement. The optional label can be used by <literal>EXIT</> statements in
- nested loops to specify which level of nesting should be
- terminated.
+ <literal>LOOP</> defines an unconditional loop that is repeated
+ indefinitely until terminated by an <literal>EXIT</> or
+ <command>RETURN</command> statement. The optional
+ <replaceable>label</replaceable> can be used by <literal>EXIT</>
+ and <literal>CONTINUE</literal> statements in nested loops to
+ specify which loop the statement should be applied to.
</para>
</sect3>
</indexterm>
<synopsis>
-<optional><<<replaceable>label</replaceable>>></optional>
+<optional> <<<replaceable>label</replaceable>>> </optional>
WHILE <replaceable>expression</replaceable> LOOP
<replaceable>statements</replaceable>
-END LOOP;
+END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
<para>
<title><literal>FOR</> (integer variant)</title>
<synopsis>
-<optional><<<replaceable>label</replaceable>>></optional>
+<optional> <<<replaceable>label</replaceable>>> </optional>
FOR <replaceable>name</replaceable> IN <optional> REVERSE </optional> <replaceable>expression</replaceable> .. <replaceable>expression</replaceable> LOOP
<replaceable>statements</replaceable>
-END LOOP;
+END LOOP <optional> <replaceable>labal</replaceable> </optional>;
</synopsis>
<para>
the results of a query and manipulate that data
accordingly. The syntax is:
<synopsis>
-<optional><<<replaceable>label</replaceable>>></optional>
+<optional> <<<replaceable>label</replaceable>>> </optional>
FOR <replaceable>record_or_row</replaceable> IN <replaceable>query</replaceable> LOOP
<replaceable>statements</replaceable>
-END LOOP;
+END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
The record or row variable is successively assigned each row
resulting from the <replaceable>query</replaceable> (which must be a
The <literal>FOR-IN-EXECUTE</> statement is another way to iterate over
rows:
<synopsis>
-<optional><<<replaceable>label</replaceable>>></optional>
+<optional> <<<replaceable>label</replaceable>>> </optional>
FOR <replaceable>record_or_row</replaceable> IN EXECUTE <replaceable>text_expression</replaceable> LOOP
<replaceable>statements</replaceable>
-END LOOP;
+END LOOP <optional> <replaceable>label</replaceable> </optional>;
</synopsis>
This is like the previous form, except that the source
<command>SELECT</command> statement is specified as a string
* procedural language
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.78 2005/07/01 17:40:29 momjian Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.79 2005/07/02 08:59:47 neilc Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
PLpgSQL_datum *initial_datum);
static void check_sql_expr(const char *stmt);
static void plpgsql_sql_error_callback(void *arg);
+static void check_labels(const char *start_label,
+ const char *end_label);
%}
int lineno;
} varname;
struct
- {
+ {
char *name;
int lineno;
PLpgSQL_rec *rec;
int n_initvars;
int *initvarnos;
} declhdr;
+ struct
+ {
+ char *end_label;
+ List *stmts;
+ } loop_body;
List *list;
PLpgSQL_type *dtype;
PLpgSQL_datum *scalar; /* a VAR, RECFIELD, or TRIGARG */
%type <forvariable> for_variable
%type <stmt> for_control
-%type <str> opt_lblname opt_label
-%type <str> opt_exitlabel
+%type <str> opt_lblname opt_block_label opt_label
%type <str> execsql_start
-%type <list> proc_sect proc_stmts stmt_else loop_body
+%type <list> proc_sect proc_stmts stmt_else
+%type <loop_body> loop_body
%type <stmt> proc_stmt pl_block
%type <stmt> stmt_assign stmt_if stmt_loop stmt_while stmt_exit
%type <stmt> stmt_return stmt_return_next stmt_raise stmt_execsql
| ';'
;
-pl_block : decl_sect K_BEGIN lno proc_sect exception_sect K_END
+pl_block : decl_sect K_BEGIN lno proc_sect exception_sect K_END opt_label
{
PLpgSQL_stmt_block *new;
new->body = $4;
new->exceptions = $5;
+ check_labels($1.label, $7);
plpgsql_ns_pop();
$$ = (PLpgSQL_stmt *)new;
;
-decl_sect : opt_label
+decl_sect : opt_block_label
{
plpgsql_ns_setlocal(false);
$$.label = $1;
$$.initvarnos = NULL;
plpgsql_add_initdatums(NULL);
}
- | opt_label decl_start
+ | opt_block_label decl_start
{
plpgsql_ns_setlocal(false);
$$.label = $1;
$$.initvarnos = NULL;
plpgsql_add_initdatums(NULL);
}
- | opt_label decl_start decl_stmts
+ | opt_block_label decl_start decl_stmts
{
plpgsql_ns_setlocal(false);
if ($3 != NULL)
plpgsql_ns_setlocal(false);
query = read_sql_stmt("");
plpgsql_ns_setlocal(true);
-
+
$$ = query;
}
;
* ... ...
* ELSE ELSE
* ... ...
- * END IF END IF
+ * END IF END IF
* END IF
*/
PLpgSQL_stmt_if *new_if;
| K_ELSE proc_sect
{
- $$ = $2;
+ $$ = $2;
}
;
-stmt_loop : opt_label K_LOOP lno loop_body
+stmt_loop : opt_block_label K_LOOP lno loop_body
{
PLpgSQL_stmt_loop *new;
new->cmd_type = PLPGSQL_STMT_LOOP;
new->lineno = $3;
new->label = $1;
- new->body = $4;
+ new->body = $4.stmts;
+ check_labels($1, $4.end_label);
plpgsql_ns_pop();
$$ = (PLpgSQL_stmt *)new;
}
;
-stmt_while : opt_label K_WHILE lno expr_until_loop loop_body
+stmt_while : opt_block_label K_WHILE lno expr_until_loop loop_body
{
PLpgSQL_stmt_while *new;
new->lineno = $3;
new->label = $1;
new->cond = $4;
- new->body = $5;
+ new->body = $5.stmts;
+ check_labels($1, $5.end_label);
plpgsql_ns_pop();
$$ = (PLpgSQL_stmt *)new;
}
;
-stmt_for : opt_label K_FOR for_control loop_body
+stmt_for : opt_block_label K_FOR for_control loop_body
{
/* This runs after we've scanned the loop body */
if ($3->cmd_type == PLPGSQL_STMT_FORI)
new = (PLpgSQL_stmt_fori *) $3;
new->label = $1;
- new->body = $4;
+ new->body = $4.stmts;
$$ = (PLpgSQL_stmt *) new;
}
else if ($3->cmd_type == PLPGSQL_STMT_FORS)
new = (PLpgSQL_stmt_fors *) $3;
new->label = $1;
- new->body = $4;
+ new->body = $4.stmts;
$$ = (PLpgSQL_stmt *) new;
}
else
Assert($3->cmd_type == PLPGSQL_STMT_DYNFORS);
new = (PLpgSQL_stmt_dynfors *) $3;
new->label = $1;
- new->body = $4;
+ new->body = $4.stmts;
$$ = (PLpgSQL_stmt *) new;
}
+ check_labels($1, $4.end_label);
/* close namespace started in opt_label */
plpgsql_ns_pop();
}
}
;
-stmt_exit : exit_type lno opt_exitlabel opt_exitcond
+stmt_exit : exit_type lno opt_label opt_exitcond
{
PLpgSQL_stmt_exit *new;
}
;
-loop_body : proc_sect K_END K_LOOP ';'
- { $$ = $1; }
+loop_body : proc_sect K_END K_LOOP opt_label ';'
+ {
+ $$.stmts = $1;
+ $$.end_label = $4;
+ }
;
stmt_execsql : execsql_start lno
}
;
-stmt_dynexecute : K_EXECUTE lno
+stmt_dynexecute : K_EXECUTE lno
{
PLpgSQL_stmt_dynexecute *new;
PLpgSQL_expr *expr;
errmsg("cursor \"%s\" has no arguments",
$3->refname)));
}
-
+
if (tok != ';')
{
plpgsql_error_lineno = plpgsql_scanner_lineno();
{ $$ = plpgsql_read_expression(K_LOOP, "LOOP"); }
;
-opt_label :
+opt_block_label :
{
plpgsql_ns_push(NULL);
$$ = NULL;
}
;
-opt_exitlabel :
- { $$ = NULL; }
+opt_label :
+ {
+ $$ = NULL;
+ }
| T_LABEL
{
- char *name;
-
- plpgsql_convert_ident(yytext, &name, 1);
- $$ = name;
+ char *label_name;
+ plpgsql_convert_ident(yytext, &label_name, 1);
+ $$ = label_name;
}
| T_WORD
{
errposition(0);
}
+static void
+check_labels(const char *start_label, const char *end_label)
+{
+ if (end_label)
+ {
+ if (!start_label)
+ {
+ plpgsql_error_lineno = plpgsql_scanner_lineno();
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("end label \"%s\" specified for unlabelled block",
+ end_label)));
+ }
+
+ if (strcmp(start_label, end_label) != 0)
+ {
+ plpgsql_error_lineno = plpgsql_scanner_lineno();
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("end label \"%s\" differs from block's label \"%s\"",
+ end_label, start_label)));
+ }
+ }
+}
+
#include "pl_scan.c"
(1 row)
drop function raise_exprs();
--- continue statement
+-- continue statement
create table conttesttbl(idx serial, v integer);
NOTICE: CREATE TABLE will create implicit sequence "conttesttbl_idx_seq" for serial column "conttesttbl.idx"
insert into conttesttbl(v) values(10);
for _i in 1..10 loop
begin
-- applies to outer loop, not the nested begin block
- continue when _i < 5;
+ continue when _i < 5;
raise notice '%', _i;
end;
end loop;
drop function continue_test2();
drop function continue_test3();
drop table conttesttbl;
+-- verbose end block and end loop
+create function end_label1() returns void as $$
+<<blbl>>
+begin
+ <<flbl1>>
+ for _i in 1 .. 10 loop
+ exit flbl1;
+ end loop flbl1;
+ <<flbl2>>
+ for _i in 1 .. 10 loop
+ exit flbl2;
+ end loop;
+end blbl;
+$$ language plpgsql;
+select end_label1();
+ end_label1
+------------
+
+(1 row)
+
+drop function end_label1();
+-- should fail: undefined end label
+create function end_label2() returns void as $$
+begin
+ for _i in 1 .. 10 loop
+ exit;
+ end loop flbl1;
+end;
+$$ language plpgsql;
+ERROR: no such label at or near "flbl1" at character 101
+LINE 5: end loop flbl1;
+ ^
+-- should fail: end label does not match start label
+create function end_label3() returns void as $$
+<<outer_label>>
+begin
+ <<inner_label>>
+ for _i in 1 .. 10 loop
+ exit;
+ end loop outer_label;
+end;
+$$ language plpgsql;
+ERROR: end label "outer_label" differs from block's label "inner_label"
+CONTEXT: compile of PL/pgSQL function "end_label3" near line 6
+-- should fail: end label on a block without a start label
+create function end_label4() returns void as $$
+<<outer_label>>
+begin
+ for _i in 1 .. 10 loop
+ exit;
+ end loop outer_label;
+end;
+$$ language plpgsql;
+ERROR: end label "outer_label" specified for unlabelled block
+CONTEXT: compile of PL/pgSQL function "end_label4" near line 5
select raise_exprs();
drop function raise_exprs();
--- continue statement
+-- continue statement
create table conttesttbl(idx serial, v integer);
insert into conttesttbl(v) values(10);
insert into conttesttbl(v) values(20);
for _i in 1..10 loop
begin
-- applies to outer loop, not the nested begin block
- continue when _i < 5;
+ continue when _i < 5;
raise notice '%', _i;
end;
end loop;
drop function continue_test2();
drop function continue_test3();
drop table conttesttbl;
+
+-- verbose end block and end loop
+create function end_label1() returns void as $$
+<<blbl>>
+begin
+ <<flbl1>>
+ for _i in 1 .. 10 loop
+ exit flbl1;
+ end loop flbl1;
+ <<flbl2>>
+ for _i in 1 .. 10 loop
+ exit flbl2;
+ end loop;
+end blbl;
+$$ language plpgsql;
+
+select end_label1();
+drop function end_label1();
+
+-- should fail: undefined end label
+create function end_label2() returns void as $$
+begin
+ for _i in 1 .. 10 loop
+ exit;
+ end loop flbl1;
+end;
+$$ language plpgsql;
+
+-- should fail: end label does not match start label
+create function end_label3() returns void as $$
+<<outer_label>>
+begin
+ <<inner_label>>
+ for _i in 1 .. 10 loop
+ exit;
+ end loop outer_label;
+end;
+$$ language plpgsql;
+
+-- should fail: end label on a block without a start label
+create function end_label4() returns void as $$
+<<outer_label>>
+begin
+ for _i in 1 .. 10 loop
+ exit;
+ end loop outer_label;
+end;
+$$ language plpgsql;
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