Add support for an optional INTO clause to PL/PgSQL's EXECUTE command.

This allows the result of executing a SELECT to be assigned to a row
variable, record variable, or list of scalars. Docs and regression tests
updated. Per Pavel Stehule, improvements and cleanup by Neil Conway.

3 files changed, 76 insertions, 6 deletions

diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index 028323192fa..d1823d7a091 100644
--- a/src/pl/plpgsql/src/gram.y
+++ b/src/pl/plpgsql/src/gram.y
@@ -4,7 +4,7 @@
  *						  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.72 2005/05/26 04:08:31 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.73 2005/06/07 02:47:16 neilc Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1250,19 +1250,62 @@ stmt_execsql	: execsql_start lno
 					}
 				;
 
-stmt_dynexecute : K_EXECUTE lno expr_until_semi
+stmt_dynexecute : K_EXECUTE lno 
 					{
 						PLpgSQL_stmt_dynexecute *new;
+						PLpgSQL_expr *expr;
+						int endtoken;
+
+						expr = read_sql_construct(K_INTO, ';', "INTO|;", "SELECT ",
+												  true, true, &endtoken);
 
 						new = palloc(sizeof(PLpgSQL_stmt_dynexecute));
 						new->cmd_type = PLPGSQL_STMT_DYNEXECUTE;
 						new->lineno   = $2;
-						new->query	  = $3;
+						new->query    = expr;
+
+						new->rec = NULL;
+						new->row = NULL;
+
+						/*
+						 * If we saw "INTO", look for an additional
+						 * row or record var.
+						 */
+						if (endtoken == K_INTO)
+						{
+							switch (yylex())
+							{
+								case T_ROW:
+									check_assignable((PLpgSQL_datum *) yylval.row);
+									new->row = yylval.row;
+									break;
+
+								case T_RECORD:
+									check_assignable((PLpgSQL_datum *) yylval.row);
+									new->rec = yylval.rec;
+									break;
+
+								case T_SCALAR:
+									new->row = read_into_scalar_list(yytext, yylval.scalar);
+									break;
+
+								default:
+									plpgsql_error_lineno = $2;
+									ereport(ERROR,
+											(errcode(ERRCODE_SYNTAX_ERROR),
+											 errmsg("syntax error at \"%s\"",
+													yytext),
+											 errdetail("Expected record or row variable.")));
+							}
+							if (yylex() != ';')
+								yyerror("syntax error");
+						}
 
 						$$ = (PLpgSQL_stmt *)new;
 					}
 				;
 
+
 stmt_open		: K_OPEN lno cursor_varptr
 					{
 						PLpgSQL_stmt_open *new;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 3c6216a3e56..1fe1ed4cbed 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.141 2005/05/26 04:08:31 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.142 2005/06/07 02:47:17 neilc Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -2202,6 +2202,13 @@ exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 	Oid			restype;
 	char	   *querystr;
 	int			exec_res;
+	PLpgSQL_rec *rec = NULL;
+	PLpgSQL_row *row = NULL;
+
+	if (stmt->rec != NULL)
+		rec = (PLpgSQL_rec *) (estate->datums[stmt->rec->recno]);
+	else if (stmt->row != NULL)
+		row = (PLpgSQL_row *) (estate->datums[stmt->row->rowno]);
 
 	/*
 	 * First we evaluate the string expression after the EXECUTE keyword.
@@ -2221,9 +2228,27 @@ exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 	/*
 	 * Call SPI_execute() without preparing a saved plan. The returncode can
 	 * be any standard OK.	Note that while a SELECT is allowed, its
-	 * results will be discarded.
+	 * results will be discarded unless an INTO clause is specified.
 	 */
 	exec_res = SPI_execute(querystr, estate->readonly_func, 0);
+
+	/* Assign to INTO variable */
+	if (rec || row)
+	{
+		if (exec_res != SPI_OK_SELECT)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("EXECUTE ... INTO is only for SELECT")));
+		else
+		{
+			if (SPI_processed == 0)
+				exec_move_row(estate, rec, row, NULL, SPI_tuptable->tupdesc);
+			else
+				exec_move_row(estate, rec, row,
+							  SPI_tuptable->vals[0], SPI_tuptable->tupdesc);
+		}
+	}
+
 	switch (exec_res)
 	{
 		case SPI_OK_SELECT:
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 17a466e01e8..a70553ac2c8 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.60 2005/05/26 04:08:31 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.61 2005/06/07 02:47:18 neilc Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -524,6 +524,8 @@ typedef struct
 {								/* Dynamic SQL string to execute */
 	int			cmd_type;
 	int			lineno;
+	PLpgSQL_rec *rec;					/* INTO record or row variable */
+	PLpgSQL_row *row;
 	PLpgSQL_expr *query;
 } PLpgSQL_stmt_dynexecute;