plpgsql functions can return RECORD, per Neil Conway.

Author: tglsfdc

doc/src/sgml/plpgsql.sgml

@@ -1,5 +1,5 @@
 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.5 2002/08/30 00:28:40 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/plpgsql.sgml,v 1.6 2002/09/01 16:28:05 tgl Exp $
 -->
 
 <chapter id="plpgsql"> 
@@ -538,8 +538,6 @@ END;
 
    <para>
     Note that <literal>RECORD</> is not a true data type, only a placeholder.
-    Thus, for example, one cannot declare a function returning
-    <literal>RECORD</>.
    </para>
   </sect2>
 

doc/src/sgml/xfunc.sgml

@@ -1,5 +1,5 @@
 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.59 2002/08/30 00:28:40 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.60 2002/09/01 16:28:05 tgl Exp $
 -->
 
  <chapter id="xfunc">
@@ -2119,6 +2119,27 @@ SELECT * FROM vw_getfoo;
 </programlisting>
     are all valid statements.
    </para>
+
+   <para>
+    In some cases it is useful to define table functions that can return
+    different column sets depending on how they are invoked.  To support this,
+    the table function can be declared as returning the pseudo-type
+    <type>record</>.  When such a function is used in a query, the expected
+    row structure must be specified in the query itself, so that the system
+    can know how to parse and plan the query.  Consider this example:
+<programlisting>
+SELECT *
+FROM dblink('dbname=template1', 'select proname, prosrc from pg_proc')
+  AS t1(proname name, prosrc text)
+WHERE proname LIKE 'bytea%';
+</programlisting>
+    The <literal>dblink</> function executes a remote query (see
+    <literal>contrib/dblink</>).  It is declared to return <type>record</>
+    since it might be used for any kind of query.  The actual column set
+    must be specified in the calling query so that the parser knows, for
+    example, what <literal>*</> should expand to.
+   </para>
+
   </sect1>
 
   <sect1 id="xfunc-plhandler">

src/pl/plpgsql/src/gram.y

@@ -4,7 +4,7 @@
  *						  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.36 2002/08/30 00:28:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.37 2002/09/01 16:28:06 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1159,7 +1159,6 @@ stmt_return		: K_RETURN lno
 					}
 				;
 
-/* FIXME: this syntax needs work, RETURN NEXT breaks stmt_return */
 stmt_return_next: K_RETURN_NEXT lno
 					{
 						PLpgSQL_stmt_return_next *new;

src/pl/plpgsql/src/pl_comp.c

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.49 2002/08/30 00:28:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.50 2002/09/01 16:28:06 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -211,11 +211,11 @@ plpgsql_compile(Oid fn_oid, int functype)
 					 procStruct->prorettype);
 			typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
 
-			/* Disallow pseudotype result, except VOID */
-			/* XXX someday allow RECORD? */
+			/* Disallow pseudotype result, except VOID or RECORD */
 			if (typeStruct->typtype == 'p')
 			{
-				if (procStruct->prorettype == VOIDOID)
+				if (procStruct->prorettype == VOIDOID ||
+					procStruct->prorettype == RECORDOID)
 					/* okay */;
 				else if (procStruct->prorettype == TRIGGEROID ||
 						 procStruct->prorettype == OPAQUEOID)
@@ -227,7 +227,8 @@ plpgsql_compile(Oid fn_oid, int functype)
 						 format_type_be(procStruct->prorettype));
 			}
 
-			if (typeStruct->typrelid != InvalidOid)
+			if (typeStruct->typrelid != InvalidOid ||
+				procStruct->prorettype == RECORDOID)
 				function->fn_retistuple = true;
 			else
 			{
@@ -486,8 +487,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 	}
 
 	/*
-	 * Create the magic found variable indicating if the last FOR or
-	 * SELECT statement returned data
+	 * Create the magic FOUND variable.
 	 */
 	var = malloc(sizeof(PLpgSQL_var));
 	memset(var, 0, sizeof(PLpgSQL_var));

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 1.61 2002/08/30 23:59:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.62 2002/09/01 16:28:06 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1588,9 +1588,9 @@ static int
 exec_stmt_return_next(PLpgSQL_execstate *estate,
 					  PLpgSQL_stmt_return_next *stmt)
 {
-	TupleDesc tupdesc;
-	int		 natts;
-	HeapTuple tuple;
+	TupleDesc	tupdesc;
+	int			natts;
+	HeapTuple	tuple;
 	bool		free_tuple = false;
 
 	if (!estate->retisset)

src/test/regress/expected/plpgsql.out

@@ -1680,3 +1680,56 @@ select * from test_ret_set_scalar(1,10);
                   11
 (10 rows)
 
+create function test_ret_set_rec_dyn(int) returns setof record as '
+DECLARE
+	retval RECORD;
+BEGIN
+	IF $1 > 10 THEN
+		SELECT INTO retval 5, 10, 15;
+		RETURN NEXT retval;
+		RETURN NEXT retval;
+	ELSE
+		SELECT INTO retval 50, 5::numeric, ''xxx''::text;
+		RETURN NEXT retval;
+		RETURN NEXT retval;
+	END IF;
+	RETURN;
+END;' language 'plpgsql';
+SELECT * FROM test_ret_set_rec_dyn(1500) AS (a int, b int, c int);
+ a | b  | c  
+---+----+----
+ 5 | 10 | 15
+ 5 | 10 | 15
+(2 rows)
+
+SELECT * FROM test_ret_set_rec_dyn(5) AS (a int, b numeric, c text);
+ a  | b |  c  
+----+---+-----
+ 50 | 5 | xxx
+ 50 | 5 | xxx
+(2 rows)
+
+create function test_ret_rec_dyn(int) returns record as '
+DECLARE
+	retval RECORD;
+BEGIN
+	IF $1 > 10 THEN
+		SELECT INTO retval 5, 10, 15;
+		RETURN retval;
+	ELSE
+		SELECT INTO retval 50, 5::numeric, ''xxx''::text;
+		RETURN retval;
+	END IF;
+END;' language 'plpgsql';
+SELECT * FROM test_ret_rec_dyn(1500) AS (a int, b int, c int);
+ a | b  | c  
+---+----+----
+ 5 | 10 | 15
+(1 row)
+
+SELECT * FROM test_ret_rec_dyn(5) AS (a int, b numeric, c text);
+ a  | b |  c  
+----+---+-----
+ 50 | 5 | xxx
+(1 row)
+

src/test/regress/sql/plpgsql.sql

@@ -1524,3 +1524,38 @@ BEGIN
 END;' language 'plpgsql';
 
 select * from test_ret_set_scalar(1,10);
+
+create function test_ret_set_rec_dyn(int) returns setof record as '
+DECLARE
+	retval RECORD;
+BEGIN
+	IF $1 > 10 THEN
+		SELECT INTO retval 5, 10, 15;
+		RETURN NEXT retval;
+		RETURN NEXT retval;
+	ELSE
+		SELECT INTO retval 50, 5::numeric, ''xxx''::text;
+		RETURN NEXT retval;
+		RETURN NEXT retval;
+	END IF;
+	RETURN;
+END;' language 'plpgsql';
+
+SELECT * FROM test_ret_set_rec_dyn(1500) AS (a int, b int, c int);
+SELECT * FROM test_ret_set_rec_dyn(5) AS (a int, b numeric, c text);
+
+create function test_ret_rec_dyn(int) returns record as '
+DECLARE
+	retval RECORD;
+BEGIN
+	IF $1 > 10 THEN
+		SELECT INTO retval 5, 10, 15;
+		RETURN retval;
+	ELSE
+		SELECT INTO retval 50, 5::numeric, ''xxx''::text;
+		RETURN retval;
+	END IF;
+END;' language 'plpgsql';
+
+SELECT * FROM test_ret_rec_dyn(1500) AS (a int, b int, c int);
+SELECT * FROM test_ret_rec_dyn(5) AS (a int, b numeric, c text);