Cause plpgsql's PERFORM to behave according to its documentation,

which says that PERFORM will execute any SELECT query and discard the
result.  The former implementation would in fact raise an error if the
result contained more than one row or more than one column.

Also, change plpgsql's error-logging mechanism to emit the additional
messages about error location at NOTICE rather than DEBUG level.  This
allows them to be seen by the client without having to dig into the
postmaster log file (which may be nonexistent or inaccessible by the
client).

1 files changed, 39 insertions, 14 deletions

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 1ad04739a33..dc5fed5cf7a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.43 2001/05/21 14:22:19 wieck Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.44 2001/05/28 19:33:24 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -185,7 +185,7 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 		 */
 		if (error_info_func != NULL)
 		{
-			elog(DEBUG, "Last error occured while executing PL/pgSQL function %s",
+			elog(NOTICE, "Error occurred while executing PL/pgSQL function %s",
 				 error_info_func->fn_name);
 			if (error_info_stmt != NULL)
 			{
@@ -248,15 +248,15 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 						stmttype = "unknown";
 						break;
 				}
-				elog(DEBUG, "line %d at %s", error_info_stmt->lineno,
+				elog(NOTICE, "line %d at %s", error_info_stmt->lineno,
 					 stmttype);
 			}
 			else
 			{
 				if (error_info_text != NULL)
-					elog(DEBUG, "%s", error_info_text);
+					elog(NOTICE, "%s", error_info_text);
 				else
-					elog(DEBUG, "no more error information available");
+					elog(NOTICE, "no more error information available");
 			}
 
 			error_info_func = NULL;
@@ -491,7 +491,7 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 		 */
 		if (error_info_func != NULL)
 		{
-			elog(DEBUG, "Last error occured while executing PL/pgSQL function %s",
+			elog(NOTICE, "Error occurred while executing PL/pgSQL function %s",
 				 error_info_func->fn_name);
 			if (error_info_stmt != NULL)
 			{
@@ -548,15 +548,15 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 						stmttype = "unknown";
 						break;
 				}
-				elog(DEBUG, "line %d at %s", error_info_stmt->lineno,
+				elog(NOTICE, "line %d at %s", error_info_stmt->lineno,
 					 stmttype);
 			}
 			else
 			{
 				if (error_info_text != NULL)
-					elog(DEBUG, "%s", error_info_text);
+					elog(NOTICE, "%s", error_info_text);
 				else
-					elog(DEBUG, "no more error information available");
+					elog(NOTICE, "no more error information available");
 			}
 
 			error_info_func = NULL;
@@ -1065,15 +1065,41 @@ exec_stmt(PLpgSQL_execstate * estate, PLpgSQL_stmt * stmt)
 /* ----------
  * exec_stmt_assign			Evaluate an expression and
  *					put the result into a variable.
+ *
+ * For no very good reason, this is also used for PERFORM statements.
  * ----------
  */
 static int
 exec_stmt_assign(PLpgSQL_execstate * estate, PLpgSQL_stmt_assign * stmt)
 {
-	if (stmt->varno < 0)
-		exec_assign_expr(estate, NULL, stmt->expr);
+	PLpgSQL_expr   *expr = stmt->expr;
+
+	if (stmt->varno >= 0)
+		exec_assign_expr(estate, estate->datums[stmt->varno], expr);
 	else
-		exec_assign_expr(estate, estate->datums[stmt->varno], stmt->expr);
+	{
+		/*
+		 * PERFORM: evaluate query and discard result.  This cannot share
+		 * code with the assignment case since we do not wish to constraint
+		 * the discarded result to be only one row/column.
+		 */
+		int			rc;
+
+		SPI_tuptable = NULL;
+		SPI_processed = 0;
+
+		/*
+		 * If not already done create a plan for this expression
+		 */
+		if (expr->plan == NULL)
+			exec_prepare_plan(estate, expr);
+
+		rc = exec_run_select(estate, expr, 0, NULL);
+		if (rc != SPI_OK_SELECT)
+			elog(ERROR, "query \"%s\" didn't return data", expr->query);
+
+		SPI_freetuptable(SPI_tuptable);
+	}
 
 	return PLPGSQL_RC_OK;
 }
@@ -2608,8 +2634,7 @@ exec_assign_expr(PLpgSQL_execstate * estate, PLpgSQL_datum * target,
 	bool		isnull = false;
 
 	value = exec_eval_expr(estate, expr, &isnull, &valtype);
-	if (target != NULL)
-		exec_assign_value(estate, target, value, valtype, &isnull);
+	exec_assign_value(estate, target, value, valtype, &isnull);
 
 	SPI_freetuptable(SPI_tuptable);
 }