From 726220fb9faad7dc6ec32990f52180f4c9b6966e Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 5 Apr 2005 18:05:46 +0000
Subject: [PATCH] Adjust grammar for plpgsql's OPEN command so that a cursor
 can be OPENed on non-SELECT commands such as EXPLAIN or SHOW (anything that
 returns tuples is allowed).  This flexibility already existed for bound
 cursors, but OPEN was artificially restricting what it would take.  Per a
 gripe some months back.

---
 doc/src/sgml/plpgsql.sgml | 18 ++++++++++--------
 src/pl/plpgsql/src/gram.y | 30 ++++++++----------------------
 2 files changed, 18 insertions(+), 30 deletions(-)

diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bd6f0254c3..3ea1ac19b2 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.63 2005/04/05 06:22:14 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.64 2005/04/05 18:05:45 tgl Exp $
 -->
 
 <chapter id="plpgsql"> 
@@ -2179,19 +2179,21 @@ DECLARE
     </para>
 
     <sect3>
-     <title><command>OPEN FOR SELECT</command></title>
+     <title><command>OPEN FOR</command> <replaceable>query</replaceable></title>
 
 <synopsis>
-OPEN <replaceable>unbound_cursor</replaceable> FOR SELECT ...;
+OPEN <replaceable>unbound_cursor</replaceable> FOR <replaceable>query</replaceable> ;
 </synopsis>
 
        <para>
-    The cursor variable is opened and given the specified query to
+        The cursor variable is opened and given the specified query to
         execute.  The cursor cannot be open already, and it must have been
         declared as an unbound cursor (that is, as a simple
-        <type>refcursor</> variable).  The <command>SELECT</command> query
-        is treated in the same way as other <command>SELECT</command>
-        statements in <application>PL/pgSQL</>: <application>PL/pgSQL</>
+        <type>refcursor</> variable).  The query must be a
+        <command>SELECT</command>, or something else that returns rows
+        (such as <command>EXPLAIN</>).  The query
+        is treated in the same way as other SQL commands in
+        <application>PL/pgSQL</>: <application>PL/pgSQL</>
         variable names are substituted, and the query plan is cached for
         possible reuse.
        </para>
@@ -2216,7 +2218,7 @@ OPEN <replaceable>unbound_cursor</replaceable> FOR EXECUTE <replaceable class="c
           execute.  The cursor cannot be open already, and it must have been
           declared as an unbound cursor (that is, as a simple
           <type>refcursor</> variable).  The query is specified as a string
-          expression in the same way as in the <command>EXECUTE</command>
+          expression, in the same way as in the <command>EXECUTE</command>
           command.  As usual, this gives flexibility so the query can vary
           from one run to the next.
        </para>
diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index e2b5c7aab1..65b8f5f409 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 1.67 2005/04/05 06:22:16 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.68 2005/04/05 18:05:46 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1276,7 +1276,6 @@ stmt_open		: K_OPEN lno cursor_varptr
 						if ($3->cursor_explicit_expr == NULL)
 						{
 						    tok = yylex();
-
 							if (tok != K_FOR)
 							{
 								plpgsql_error_lineno = $2;
@@ -1288,26 +1287,15 @@ stmt_open		: K_OPEN lno cursor_varptr
 							}
 
 							tok = yylex();
-							switch (tok)
+							if (tok == K_EXECUTE)
 							{
-								case K_SELECT:
-								case '(':
-									plpgsql_push_back_token(tok);
-									new->query = read_sql_stmt("");
-									break;
-
-								case K_EXECUTE:
-									new->dynquery = read_sql_stmt("SELECT ");
-									break;
-
-								default:
-									plpgsql_error_lineno = $2;
-									ereport(ERROR,
-											(errcode(ERRCODE_SYNTAX_ERROR),
-											 errmsg("syntax error at \"%s\"",
-													yytext)));
+								new->dynquery = read_sql_stmt("SELECT ");
+							}
+							else
+							{
+								plpgsql_push_back_token(tok);
+								new->query = read_sql_stmt("");
 							}
-
 						}
 						else
 						{
@@ -1316,7 +1304,6 @@ stmt_open		: K_OPEN lno cursor_varptr
 								char   *cp;
 
 								tok = yylex();
-
 								if (tok != '(')
 								{
 									plpgsql_error_lineno = plpgsql_scanner_lineno();
@@ -1369,7 +1356,6 @@ stmt_open		: K_OPEN lno cursor_varptr
 							else
 							{
 								tok = yylex();
-
 								if (tok == '(')
 								{
 									plpgsql_error_lineno = plpgsql_scanner_lineno();
-- 
2.40.0