From 6918df16a5483600fb0466b96f813ed5b6927fd8 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 24 Jun 2002 23:12:06 +0000
Subject: [PATCH] plpgsql's PERFORM statement now sets FOUND depending on
whether any rows were returned by the performed query. Per recent
pgsql-general discussion.
---
doc/src/sgml/plsql.sgml | 12 +++++-------
src/pl/plpgsql/src/pl_exec.c | 12 ++++++++----
2 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/doc/src/sgml/plsql.sgml b/doc/src/sgml/plsql.sgml
index 91e96c77f06..082b77fc5b2 100644
--- a/doc/src/sgml/plsql.sgml
+++ b/doc/src/sgml/plsql.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/Attic/plsql.sgml,v 2.59 2002/06/15 19:34:51 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/Attic/plsql.sgml,v 2.60 2002/06/24 23:12:06 tgl Exp $
-->
<chapter id="plpgsql">
@@ -903,7 +903,9 @@ PERFORM <replaceable>query</replaceable>;
This executes a <literal>SELECT</literal>
<replaceable>query</replaceable> and discards the
result. <application>PL/pgSQL</application> variables are substituted
- in the query as usual.
+ in the query as usual. Also, the special variable FOUND is set to
+ true if the query produced at least one row, or false if it produced
+ no rows.
</para>
<note>
@@ -916,11 +918,7 @@ PERFORM <replaceable>query</replaceable>;
<para>
An example:
<programlisting>
-PERFORM create_mv(''cs_session_page_requests_mv'',''
- SELECT session_id, page_id, count(*) AS n_hits,
- sum(dwell_time) AS dwell_time, count(dwell_time) AS dwell_count
- FROM cs_fact_table
- GROUP BY session_id, page_id '');
+PERFORM create_mv(''cs_session_page_requests_mv'', my_query);
</programlisting>
</para>
</sect2>
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index ab539dc928a..abfce9b8bd2 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 1.55 2002/03/25 07:41:10 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.56 2002/06/24 23:12:06 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -969,9 +969,11 @@ exec_stmt_assign(PLpgSQL_execstate * estate, PLpgSQL_stmt_assign * stmt)
else
{
/*
- * 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.
+ * PERFORM: evaluate query and discard result (but set FOUND
+ * depending on whether at least one row was returned).
+ *
+ * This cannot share code with the assignment case since we do not
+ * wish to constrain the discarded result to be only one row/column.
*/
int rc;
@@ -985,6 +987,8 @@ exec_stmt_assign(PLpgSQL_execstate * estate, PLpgSQL_stmt_assign * stmt)
if (rc != SPI_OK_SELECT)
elog(ERROR, "query \"%s\" didn't return data", expr->query);
+ exec_set_found(estate, (estate->eval_processed != 0));
+
exec_eval_cleanup(estate);
}
--
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