Skip to content

Commit 309cd7c

Browse files
tglsfdctglsfdc
committed
Add "USING expressions" option to plpgsql's OPEN cursor FOR EXECUTE.
This is the last EXECUTE-like plpgsql statement that was missing the capability of inserting parameter values via USING. Pavel Stehule, reviewed by Itagaki Takahiro
1 parent 8ab27af commit 309cd7c

File tree

7 files changed

+131
-61
lines changed

7 files changed

+131
-61
lines changed

‎doc/src/sgml/plpgsql.sgml‎

Lines changed: 13 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.149 2009/12/28 19:11:51 petere Exp $ -->
1+
<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.150 2010/01/19 01:35:30 tgl Exp $ -->
22

33
<chapter id="plpgsql">
44
<title><application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language</title>
@@ -1016,7 +1016,7 @@ END;
10161016
<command>EXECUTE</command> statement is provided:
10171017

10181018
<synopsis>
1019-
EXECUTE <replaceable class="command">command-string</replaceable> <optional> INTO <optional>STRICT</optional> <replaceable>target</replaceable> </optional> <optional> USING <replaceable>expression</replaceable> <optional>, ...</optional> </optional>;
1019+
EXECUTE <replaceable class="command">command-string</replaceable> <optional> INTO <optional>STRICT</optional> <replaceable>target</replaceable> </optional> <optional> USING <replaceable>expression</replaceable> <optional>, ... </optional> </optional>;
10201020
</synopsis>
10211021

10221022
where <replaceable>command-string</replaceable> is an expression
@@ -1500,7 +1500,7 @@ RETURN <replaceable>expression</replaceable>;
15001500
<synopsis>
15011501
RETURN NEXT <replaceable>expression</replaceable>;
15021502
RETURN QUERY <replaceable>query</replaceable>;
1503-
RETURN QUERY EXECUTE <replaceable class="command">command-string</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ...</optional> </optional>;
1503+
RETURN QUERY EXECUTE <replaceable class="command">command-string</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ... </optional> </optional>;
15041504
</synopsis>
15051505

15061506
<para>
@@ -2190,7 +2190,7 @@ $$ LANGUAGE plpgsql;
21902190
rows:
21912191
<synopsis>
21922192
<optional> &lt;&lt;<replaceable>label</replaceable>&gt;&gt; </optional>
2193-
FOR <replaceable>target</replaceable> IN EXECUTE <replaceable>text_expression</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ...</optional> </optional> LOOP
2193+
FOR <replaceable>target</replaceable> IN EXECUTE <replaceable>text_expression</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ... </optional> </optional> LOOP
21942194
<replaceable>statements</replaceable>
21952195
END LOOP <optional> <replaceable>label</replaceable> </optional>;
21962196
</synopsis>
@@ -2495,7 +2495,7 @@ OPEN curs1 FOR SELECT * FROM foo WHERE key = mykey;
24952495
<title><command>OPEN FOR EXECUTE</command></title>
24962496

24972497
<synopsis>
2498-
OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO </optional> SCROLL </optional> FOR EXECUTE <replaceable class="command">query_string</replaceable>;
2498+
OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO </optional> SCROLL </optional> FOR EXECUTE <replaceable class="command">query_string</replaceable> <optional> USING <replaceable>expression</replaceable> <optional>, ... </optional> </optional>;
24992499
</synopsis>
25002500

25012501
<para>
@@ -2507,7 +2507,8 @@ OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO </opt
25072507
command. As usual, this gives flexibility so the query plan can vary
25082508
from one run to the next (see <xref linkend="plpgsql-plan-caching">),
25092509
and it also means that variable substitution is not done on the
2510-
command string.
2510+
command string. As with <command>EXECUTE</command>, parameter values
2511+
can be inserted into the dynamic command via <literal>USING</>.
25112512
The <literal>SCROLL</> and
25122513
<literal>NO SCROLL</> options have the same meanings as for a bound
25132514
cursor.
@@ -2516,8 +2517,12 @@ OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO </opt
25162517
<para>
25172518
An example:
25182519
<programlisting>
2519-
OPEN curs1 FOR EXECUTE 'SELECT * FROM ' || quote_ident($1);
2520+
OPEN curs1 FOR EXECUTE 'SELECT * FROM ' || quote_ident(tabname) ' WHERE col1 = $1' USING keyvalue;
25202521
</programlisting>
2522+
In this example, the table name is inserted into the query textually,
2523+
so use of <function>quote_ident()</> is recommended to guard against
2524+
SQL injection. The comparison value for <literal>col1</> is inserted
2525+
via a <literal>USING</> parameter, so it needs no quoting.
25212526
</para>
25222527
</sect3>
25232528

@@ -2893,7 +2898,7 @@ END LOOP <optional> <replaceable>label</replaceable> </optional>;
28932898
raise errors.
28942899

28952900
<synopsis>
2896-
RAISE <optional> <replaceable class="parameter">level</replaceable> </optional> '<replaceable class="parameter">format</replaceable>' <optional>, <replaceable class="parameter">expression</replaceable> <optional>, ...</optional></optional> <optional> USING <replaceable class="parameter">option</replaceable> = <replaceable class="parameter">expression</replaceable> <optional>, ... </optional> </optional>;
2901+
RAISE <optional> <replaceable class="parameter">level</replaceable> </optional> '<replaceable class="parameter">format</replaceable>' <optional>, <replaceable class="parameter">expression</replaceable> <optional>, ... </optional></optional> <optional> USING <replaceable class="parameter">option</replaceable> = <replaceable class="parameter">expression</replaceable> <optional>, ... </optional> </optional>;
28972902
RAISE <optional> <replaceable class="parameter">level</replaceable> </optional> <replaceable class="parameter">condition_name</> <optional> USING <replaceable class="parameter">option</replaceable> = <replaceable class="parameter">expression</replaceable> <optional>, ... </optional> </optional>;
28982903
RAISE <optional> <replaceable class="parameter">level</replaceable> </optional> SQLSTATE '<replaceable class="parameter">sqlstate</>' <optional> USING <replaceable class="parameter">option</replaceable> = <replaceable class="parameter">expression</replaceable> <optional>, ... </optional> </optional>;
28992904
RAISE <optional> <replaceable class="parameter">level</replaceable> </optional> USING <replaceable class="parameter">option</replaceable> = <replaceable class="parameter">expression</replaceable> <optional>, ... </optional>;

‎src/pl/plpgsql/src/gram.y‎

Lines changed: 22 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.139 2010/01/10 17:56:50 tgl Exp $
11+
* $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.140 2010/01/19 01:35:30 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -1704,7 +1704,27 @@ stmt_open : K_OPEN cursor_variable
17041704
tok = yylex();
17051705
if (tok == K_EXECUTE)
17061706
{
1707-
new->dynquery = read_sql_stmt("SELECT ");
1707+
int endtoken;
1708+
1709+
new->dynquery =
1710+
read_sql_expression2(K_USING, ';',
1711+
"USING or ;",
1712+
&endtoken);
1713+
1714+
/* If we found "USING", collect argument(s) */
1715+
if (endtoken == K_USING)
1716+
{
1717+
PLpgSQL_expr *expr;
1718+
1719+
do
1720+
{
1721+
expr = read_sql_expression2(',', ';',
1722+
", or ;",
1723+
&endtoken);
1724+
new->params = lappend(new->params,
1725+
expr);
1726+
} while (endtoken == ',');
1727+
}
17081728
}
17091729
else
17101730
{

‎src/pl/plpgsql/src/pl_exec.c‎

Lines changed: 22 additions & 48 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.253 2010/01/02 16:58:13 momjian Exp $
11+
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.254 2010/01/19 01:35:31 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -200,7 +200,8 @@ static PreparedParamsData *exec_eval_using_params(PLpgSQL_execstate *estate,
200200
List *params);
201201
static void free_params_data(PreparedParamsData *ppd);
202202
static Portal exec_dynquery_with_params(PLpgSQL_execstate *estate,
203-
PLpgSQL_expr *query, List *params);
203+
PLpgSQL_expr *dynquery, List *params,
204+
const char *portalname, int cursorOptions);
204205

205206

206207
/* ----------
@@ -2337,7 +2338,7 @@ exec_stmt_return_query(PLpgSQL_execstate *estate,
23372338
/* RETURN QUERY EXECUTE */
23382339
Assert(stmt->dynquery != NULL);
23392340
portal = exec_dynquery_with_params(estate, stmt->dynquery,
2340-
stmt->params);
2341+
stmt->params, NULL, 0);
23412342
}
23422343

23432344
tupmap = convert_tuples_by_position(portal->tupDesc,
@@ -3133,7 +3134,8 @@ exec_stmt_dynfors(PLpgSQL_execstate *estate, PLpgSQL_stmt_dynfors *stmt)
31333134
Portal portal;
31343135
int rc;
31353136

3136-
portal = exec_dynquery_with_params(estate, stmt->query, stmt->params);
3137+
portal = exec_dynquery_with_params(estate, stmt->query, stmt->params,
3138+
NULL, 0);
31373139

31383140
/*
31393141
* Execute the loop
@@ -3161,7 +3163,6 @@ exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt)
31613163
PLpgSQL_expr *query;
31623164
Portal portal;
31633165
ParamListInfo paramLI;
3164-
bool isnull;
31653166

31663167
/* ----------
31673168
* Get the cursor variable and if it has an assigned name, check
@@ -3201,43 +3202,11 @@ exec_stmt_open(PLpgSQL_execstate *estate, PLpgSQL_stmt_open *stmt)
32013202
* This is an OPEN refcursor FOR EXECUTE ...
32023203
* ----------
32033204
*/
3204-
Datum queryD;
3205-
Oid restype;
3206-
char *querystr;
3207-
SPIPlanPtr curplan;
3208-
3209-
/* ----------
3210-
* We evaluate the string expression after the
3211-
* EXECUTE keyword. It's result is the querystring we have
3212-
* to execute.
3213-
* ----------
3214-
*/
3215-
queryD = exec_eval_expr(estate, stmt->dynquery, &isnull, &restype);
3216-
if (isnull)
3217-
ereport(ERROR,
3218-
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
3219-
errmsg("query string argument of EXECUTE is null")));
3220-
3221-
/* Get the C-String representation */
3222-
querystr = convert_value_to_string(queryD, restype);
3223-
3224-
exec_eval_cleanup(estate);
3225-
3226-
/* ----------
3227-
* Now we prepare a query plan for it and open a cursor
3228-
* ----------
3229-
*/
3230-
curplan = SPI_prepare_cursor(querystr, 0, NULL, stmt->cursor_options);
3231-
if (curplan == NULL)
3232-
elog(ERROR, "SPI_prepare_cursor failed for \"%s\": %s",
3233-
querystr, SPI_result_code_string(SPI_result));
3234-
portal = SPI_cursor_open(curname, curplan, NULL, NULL,
3235-
estate->readonly_func);
3236-
if (portal == NULL)
3237-
elog(ERROR, "could not open cursor for query \"%s\": %s",
3238-
querystr, SPI_result_code_string(SPI_result));
3239-
pfree(querystr);
3240-
SPI_freeplan(curplan);
3205+
portal = exec_dynquery_with_params(estate,
3206+
stmt->dynquery,
3207+
stmt->params,
3208+
curname,
3209+
stmt->cursor_options);
32413210

32423211
/*
32433212
* If cursor variable was NULL, store the generated portal name in it
@@ -5530,8 +5499,11 @@ free_params_data(PreparedParamsData *ppd)
55305499
* Open portal for dynamic query
55315500
*/
55325501
static Portal
5533-
exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *dynquery,
5534-
List *params)
5502+
exec_dynquery_with_params(PLpgSQL_execstate *estate,
5503+
PLpgSQL_expr *dynquery,
5504+
List *params,
5505+
const char *portalname,
5506+
int cursorOptions)
55355507
{
55365508
Portal portal;
55375509
Datum query;
@@ -5564,20 +5536,22 @@ exec_dynquery_with_params(PLpgSQL_execstate *estate, PLpgSQL_expr *dynquery,
55645536
PreparedParamsData *ppd;
55655537

55665538
ppd = exec_eval_using_params(estate, params);
5567-
portal = SPI_cursor_open_with_args(NULL,
5539+
portal = SPI_cursor_open_with_args(portalname,
55685540
querystr,
55695541
ppd->nargs, ppd->types,
55705542
ppd->values, ppd->nulls,
5571-
estate->readonly_func, 0);
5543+
estate->readonly_func,
5544+
cursorOptions);
55725545
free_params_data(ppd);
55735546
}
55745547
else
55755548
{
5576-
portal = SPI_cursor_open_with_args(NULL,
5549+
portal = SPI_cursor_open_with_args(portalname,
55775550
querystr,
55785551
0, NULL,
55795552
NULL, NULL,
5580-
estate->readonly_func, 0);
5553+
estate->readonly_func,
5554+
cursorOptions);
55815555
}
55825556

55835557
if (portal == NULL)

‎src/pl/plpgsql/src/pl_funcs.c‎

Lines changed: 21 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.87 2010/01/02 16:58:13 momjian Exp $
11+
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.88 2010/01/19 01:35:31 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -619,9 +619,28 @@ dump_open(PLpgSQL_stmt_open *stmt)
619619
printf(" execute = '");
620620
dump_expr(stmt->dynquery);
621621
printf("'\n");
622+
623+
if (stmt->params != NIL)
624+
{
625+
ListCell *lc;
626+
int i;
627+
628+
dump_indent += 2;
629+
dump_ind();
630+
printf(" USING\n");
631+
dump_indent += 2;
632+
i = 1;
633+
foreach(lc, stmt->params)
634+
{
635+
dump_ind();
636+
printf(" parameter $%d: ", i++);
637+
dump_expr((PLpgSQL_expr *) lfirst(lc));
638+
printf("\n");
639+
}
640+
dump_indent -= 4;
641+
}
622642
}
623643
dump_indent -= 2;
624-
625644
}
626645

627646
static void

‎src/pl/plpgsql/src/plpgsql.h‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.128 2010/01/10 17:15:18 tgl Exp $
11+
* $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.129 2010/01/19 01:35:31 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -503,6 +503,7 @@ typedef struct
503503
PLpgSQL_expr *argquery;
504504
PLpgSQL_expr *query;
505505
PLpgSQL_expr *dynquery;
506+
List *params; /* USING expressions */
506507
} PLpgSQL_stmt_open;
507508

508509

‎src/test/regress/expected/plpgsql.out‎

Lines changed: 29 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3189,6 +3189,35 @@ NOTICE: 6
31893189
26
31903190
(1 row)
31913191

3192+
drop function exc_using(int, text);
3193+
create or replace function exc_using(int) returns void as $$
3194+
declare
3195+
c refcursor;
3196+
i int;
3197+
begin
3198+
open c for execute 'select * from generate_series(1,$1)' using $1+1;
3199+
loop
3200+
fetch c into i;
3201+
exit when not found;
3202+
raise notice '%', i;
3203+
end loop;
3204+
close c;
3205+
return;
3206+
end;
3207+
$$ language plpgsql;
3208+
select exc_using(5);
3209+
NOTICE: 1
3210+
NOTICE: 2
3211+
NOTICE: 3
3212+
NOTICE: 4
3213+
NOTICE: 5
3214+
NOTICE: 6
3215+
exc_using
3216+
-----------
3217+
3218+
(1 row)
3219+
3220+
drop function exc_using(int);
31923221
-- test FOR-over-cursor
31933222
create or replace function forc01() returns void as $$
31943223
declare

‎src/test/regress/sql/plpgsql.sql‎

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2629,6 +2629,28 @@ $$ language plpgsql;
26292629

26302630
select exc_using(5, 'foobar');
26312631

2632+
drop function exc_using(int, text);
2633+
2634+
create or replace function exc_using(int) returns void as $$
2635+
declare
2636+
c refcursor;
2637+
i int;
2638+
begin
2639+
open c for execute 'select * from generate_series(1,$1)' using $1+1;
2640+
loop
2641+
fetch c into i;
2642+
exit when not found;
2643+
raise notice '%', i;
2644+
end loop;
2645+
close c;
2646+
return;
2647+
end;
2648+
$$ language plpgsql;
2649+
2650+
select exc_using(5);
2651+
2652+
drop function exc_using(int);
2653+
26322654
-- test FOR-over-cursor
26332655

26342656
create or replace function forc01() returns void as $$

0 commit comments

Comments
 (0)