diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index 8636a0a6b85628f6f3c6d99b99e8ed9c0db7d89c..7364e89b949ed109c6e6fcec13a63efcaea8ac14 100644
--- a/src/pl/plpgsql/src/gram.y
+++ b/src/pl/plpgsql/src/gram.y
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.87 2006/03/09 21:29:36 momjian Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.88 2006/03/23 04:22:36 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1714,6 +1714,44 @@ lno :
%%
+#define MAX_EXPR_PARAMS 1024
+
+/*
+ * determine the expression parameter position to use for a plpgsql datum
+ *
+ * It is important that any given plpgsql datum map to just one parameter.
+ * We used to be sloppy and assign a separate parameter for each occurrence
+ * of a datum reference, but that fails for situations such as "select DATUM
+ * from ... group by DATUM".
+ *
+ * The params[] array must be of size MAX_EXPR_PARAMS.
+ */
+static int
+assign_expr_param(int dno, int *params, int *nparams)
+{
+ int i;
+
+ /* already have an instance of this dno? */
+ for (i = 0; i < *nparams; i++)
+ {
+ if (params[i] == dno)
+ return i+1;
+ }
+ /* check for array overflow */
+ if (*nparams >= MAX_EXPR_PARAMS)
+ {
+ plpgsql_error_lineno = plpgsql_scanner_lineno();
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("too many variables specified in SQL statement")));
+ }
+ /* add new parameter dno to array */
+ params[*nparams] = dno;
+ (*nparams)++;
+ return *nparams;
+}
+
+
PLpgSQL_expr *
plpgsql_read_expression(int until, const char *expected)
{
@@ -1752,7 +1790,7 @@ read_sql_construct(int until,
PLpgSQL_dstring ds;
int parenlevel = 0;
int nparams = 0;
- int params[1024];
+ int params[MAX_EXPR_PARAMS];
char buf[32];
PLpgSQL_expr *expr;
@@ -1804,32 +1842,26 @@ read_sql_construct(int until,
if (plpgsql_SpaceScanned)
plpgsql_dstring_append(&ds, " ");
- /* Check for array overflow */
- if (nparams >= 1024)
- {
- plpgsql_error_lineno = lno;
- ereport(ERROR,
- (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
- errmsg("too many variables specified in SQL statement")));
- }
-
switch (tok)
{
case T_SCALAR:
- params[nparams] = yylval.scalar->dno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.scalar->dno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
case T_ROW:
- params[nparams] = yylval.row->rowno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.row->rowno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
case T_RECORD:
- params[nparams] = yylval.rec->recno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.rec->recno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
@@ -1927,7 +1959,7 @@ make_select_stmt(void)
{
PLpgSQL_dstring ds;
int nparams = 0;
- int params[1024];
+ int params[MAX_EXPR_PARAMS];
char buf[32];
PLpgSQL_expr *expr;
PLpgSQL_row *row = NULL;
@@ -1992,32 +2024,26 @@ make_select_stmt(void)
if (plpgsql_SpaceScanned)
plpgsql_dstring_append(&ds, " ");
- /* Check for array overflow */
- if (nparams >= 1024)
- {
- plpgsql_error_lineno = plpgsql_scanner_lineno();
- ereport(ERROR,
- (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
- errmsg("too many parameters specified in SQL statement")));
- }
-
switch (tok)
{
case T_SCALAR:
- params[nparams] = yylval.scalar->dno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.scalar->dno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
case T_ROW:
- params[nparams] = yylval.row->rowno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.row->rowno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
case T_RECORD:
- params[nparams] = yylval.rec->recno;
- snprintf(buf, sizeof(buf), " $%d ", ++nparams);
+ snprintf(buf, sizeof(buf), " $%d ",
+ assign_expr_param(yylval.rec->recno,
+ params, &nparams));
plpgsql_dstring_append(&ds, buf);
break;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index e72383bbb72c27b9e5a471cb44ce23ffd718613b..6e6597dadb2f452a7880e74c9295101efb570810 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2776,3 +2776,21 @@ NOTICE: 4 bb cc
(1 row)
+-- regression test: verify that multiple uses of same plpgsql datum within
+-- a SQL command all get mapped to the same $n parameter. The return value
+-- of the SELECT is not important, we only care that it doesn't fail with
+-- a complaint about an ungrouped column reference.
+create function multi_datum_use(p1 int) returns bool as $$
+declare
+ x int;
+ y int;
+begin
+ select into x,y unique1/p1, unique1/$1 from tenk1 group by unique1/p1;
+ return x = y;
+end$$ language plpgsql;
+select multi_datum_use(42);
+ multi_datum_use
+-----------------
+ t
+(1 row)
+
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index a2d65817b1fc4066eb52a88f622ad6a071b57f2b..19e145be65f359bc3c3d22318cab92656e31c0f0 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -2309,3 +2309,18 @@ end;
$proc$ language plpgsql;
select for_vect();
+
+-- regression test: verify that multiple uses of same plpgsql datum within
+-- a SQL command all get mapped to the same $n parameter. The return value
+-- of the SELECT is not important, we only care that it doesn't fail with
+-- a complaint about an ungrouped column reference.
+create function multi_datum_use(p1 int) returns bool as $$
+declare
+ x int;
+ y int;
+begin
+ select into x,y unique1/p1, unique1/$1 from tenk1 group by unique1/p1;
+ return x = y;
+end$$ language plpgsql;
+
+select multi_datum_use(42);