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 bd6f0254c3a..3ea1ac19b2d 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 e2b5c7aab14..65b8f5f4093 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();
--
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