diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 59ec377ea9de6f7a0b5ca601ea0474eeedc04d47..24bcf52a4f747f615bbf5476aa585697d7d0c7be 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.114 2007/07/15 00:45:16 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.115 2007/07/16 17:01:10 tgl Exp $ -->
<chapter id="plpgsql">
<title><application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language</title>
@@ -249,10 +249,23 @@ $$ LANGUAGE plpgsql;
</programlisting>
</para>
+ <note>
+ <para>
+ There is actually a hidden <quote>outer block</> surrounding the body
+ of any <application>PL/pgSQL</> function. This block provides the
+ declarations of the function's parameters (if any), as well as some
+ special variables such as <literal>FOUND</literal> (see
+ <xref linkend="plpgsql-statements-diagnostics">). The outer block is
+ labeled with the function's name, meaning that parameters and special
+ variables can be qualified with the function's name.
+ </para>
+ </note>
+
<para>
It is important not to confuse the use of
<command>BEGIN</>/<command>END</> for grouping statements in
- <application>PL/pgSQL</> with the database commands for transaction
+ <application>PL/pgSQL</> with the similarly-named SQL commands
+ for transaction
control. <application>PL/pgSQL</>'s <command>BEGIN</>/<command>END</>
are only for grouping; they do not start or end a transaction.
Functions and trigger procedures are always executed within a transaction
@@ -370,6 +383,19 @@ BEGIN
END;
$$ LANGUAGE plpgsql;
</programlisting>
+ </para>
+
+ <note>
+ <para>
+ These two examples are not perfectly equivalent. In the first case,
+ <literal>subtotal</> could be referenced as
+ <literal>sales_tax.subtotal</>, but in the second case it could not.
+ (Had we attached a label to the block, <literal>subtotal</> could
+ be qualified with that label, instead.)
+ </para>
+ </note>
+
+ <para>
Some more examples:
<programlisting>
CREATE FUNCTION instr(varchar, integer) RETURNS integer AS $$
@@ -3618,12 +3644,12 @@ a_output := a_output || $$ if v_$$ || referrer_keys.kind || $$ like '$$
<listitem>
<para>
- You cannot use parameter names that are the same as columns
- that are referenced in the function. Oracle allows you to do this
- if you qualify the parameter name using
- <literal>function_name.parameter_name</>.
- In <application>PL/pgSQL</>, you can instead avoid a conflict by
- qualifying the column or table name.
+ If a name used in a SQL command could be either a column name of a
+ table or a reference to a variable of the function,
+ <application>PL/SQL</> treats it as a column name, while
+ <application>PL/pgSQL</> treats it as a variable name. It's best
+ to avoid such ambiguities in the first place, but if necessary you
+ can fix them by properly qualifying the ambiguous name.
(See <xref linkend="plpgsql-var-subst">.)
</para>
</listitem>
diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index 0f41c999724b5726fad8710064ecd7df0d74cf56..795d3c4c4bd49acec5a19736d49f085893b1c5e0 100644
--- a/src/pl/plpgsql/src/gram.y
+++ b/src/pl/plpgsql/src/gram.y
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.103 2007/07/15 02:15:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.104 2007/07/16 17:01:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -366,7 +366,7 @@ decl_statement : decl_varname decl_const decl_datatype decl_notnull decl_defval
plpgsql_ns_rename($2, $4);
}
| decl_varname opt_scrollable K_CURSOR
- { plpgsql_ns_push(NULL); }
+ { plpgsql_ns_push($1.name); }
decl_cursor_args decl_is_for decl_cursor_query
{
PLpgSQL_var *new;
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index 0293bc3fe072ff0e3b615a1ab49afb9b48da0ab6..db150632f0555d3e8e80543220e25504540b98bc 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.116 2007/06/26 16:48:09 alvherre Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.117 2007/07/16 17:01:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -306,10 +306,12 @@ do_compile(FunctionCallInfo fcinfo,
error_context_stack = &plerrcontext;
/*
- * Initialize the compiler
+ * Initialize the compiler, particularly the namespace stack. The
+ * outermost namespace contains function parameters and other special
+ * variables (such as FOUND), and is named after the function itself.
*/
plpgsql_ns_init();
- plpgsql_ns_push(NULL);
+ plpgsql_ns_push(NameStr(procStruct->proname));
plpgsql_DumpExecTree = false;
datums_alloc = 128;
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 4d5eba73e3b43e7c3c96f74e6844cff37d7b1f3c..da128daa7f7f39ae0c22216a3541fadf322947c4 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.60 2007/07/15 02:15:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.61 2007/07/16 17:01:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -147,15 +147,14 @@ plpgsql_ns_setlocal(bool flag)
* ----------
*/
void
-plpgsql_ns_push(char *label)
+plpgsql_ns_push(const char *label)
{
PLpgSQL_ns *new;
if (label == NULL)
label = "";
- new = palloc(sizeof(PLpgSQL_ns));
- memset(new, 0, sizeof(PLpgSQL_ns));
+ new = palloc0(sizeof(PLpgSQL_ns));
new->upper = ns_current;
ns_current = new;
@@ -224,7 +223,7 @@ plpgsql_ns_additem(int itemtype, int itemno, const char *name)
* ----------
*/
PLpgSQL_nsitem *
-plpgsql_ns_lookup(char *name, char *label)
+plpgsql_ns_lookup(const char *name, const char *label)
{
PLpgSQL_ns *ns;
int i;
@@ -236,11 +235,11 @@ plpgsql_ns_lookup(char *name, char *label)
{
for (ns = ns_current; ns != NULL; ns = ns->upper)
{
- if (!strcmp(ns->items[0]->name, label))
+ if (strcmp(ns->items[0]->name, label) == 0)
{
for (i = 1; i < ns->items_used; i++)
{
- if (!strcmp(ns->items[i]->name, name))
+ if (strcmp(ns->items[i]->name, name) == 0)
return ns->items[i];
}
return NULL; /* name not found in specified label */
@@ -254,7 +253,7 @@ plpgsql_ns_lookup(char *name, char *label)
*/
for (ns = ns_current; ns != NULL; ns = ns->upper)
{
- if (!strcmp(ns->items[0]->name, name))
+ if (strcmp(ns->items[0]->name, name) == 0)
return ns->items[0];
}
@@ -265,7 +264,7 @@ plpgsql_ns_lookup(char *name, char *label)
{
for (i = 1; i < ns->items_used; i++)
{
- if (!strcmp(ns->items[i]->name, name))
+ if (strcmp(ns->items[i]->name, name) == 0)
return ns->items[i];
}
if (ns_localmode)
@@ -288,14 +287,13 @@ plpgsql_ns_rename(char *oldname, char *newname)
int i;
/*
- * Lookup name in the namestack; do the lookup in the current namespace
- * only.
+ * Lookup name in the namestack
*/
for (ns = ns_current; ns != NULL; ns = ns->upper)
{
for (i = 1; i < ns->items_used; i++)
{
- if (!strcmp(ns->items[i]->name, oldname))
+ if (strcmp(ns->items[i]->name, oldname) == 0)
{
newitem = palloc(sizeof(PLpgSQL_nsitem) + strlen(newname));
newitem->itemtype = ns->items[i]->itemtype;
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index dce7be2b1bd29fe3f09c71d45812ed6b08e13dca..6ffb8b419584faaf55dd6692d7a9bb3d7dcb0cf6 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.89 2007/07/15 02:15:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.90 2007/07/16 17:01:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -770,10 +770,10 @@ extern char *plpgsql_dstring_get(PLpgSQL_dstring *ds);
*/
extern void plpgsql_ns_init(void);
extern bool plpgsql_ns_setlocal(bool flag);
-extern void plpgsql_ns_push(char *label);
+extern void plpgsql_ns_push(const char *label);
extern void plpgsql_ns_pop(void);
extern void plpgsql_ns_additem(int itemtype, int itemno, const char *name);
-extern PLpgSQL_nsitem *plpgsql_ns_lookup(char *name, char *nsname);
+extern PLpgSQL_nsitem *plpgsql_ns_lookup(const char *name, const char *nsname);
extern void plpgsql_ns_rename(char *oldname, char *newname);
/* ----------
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index ddb44a72527d960033065293b05aa5127df168b5..6d97b63e5c93806a2e8bcb61b919efcf0138bcae 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -3051,3 +3051,31 @@ select * from sc_test();
(3 rows)
drop function sc_test();
+-- test qualified variable names
+create function pl_qual_names (param1 int) returns void as $$
+<<outerblock>>
+declare
+ param1 int := 1;
+begin
+ <<innerblock>>
+ declare
+ param1 int := 2;
+ begin
+ raise notice 'param1 = %', param1;
+ raise notice 'pl_qual_names.param1 = %', pl_qual_names.param1;
+ raise notice 'outerblock.param1 = %', outerblock.param1;
+ raise notice 'innerblock.param1 = %', innerblock.param1;
+ end;
+end;
+$$ language plpgsql;
+select pl_qual_names(42);
+NOTICE: param1 = 2
+NOTICE: pl_qual_names.param1 = 42
+NOTICE: outerblock.param1 = 1
+NOTICE: innerblock.param1 = 2
+ pl_qual_names
+---------------
+
+(1 row)
+
+drop function pl_qual_names(int);
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index ee9de0a5838e142ae2057eb9132b7f0420f33d44..d1c715e8d4cc299b1aeeee8e0e553bd51614f350 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -2535,3 +2535,25 @@ select * from sc_test();
drop function sc_test();
+-- test qualified variable names
+
+create function pl_qual_names (param1 int) returns void as $$
+<<outerblock>>
+declare
+ param1 int := 1;
+begin
+ <<innerblock>>
+ declare
+ param1 int := 2;
+ begin
+ raise notice 'param1 = %', param1;
+ raise notice 'pl_qual_names.param1 = %', pl_qual_names.param1;
+ raise notice 'outerblock.param1 = %', outerblock.param1;
+ raise notice 'innerblock.param1 = %', innerblock.param1;
+ end;
+end;
+$$ language plpgsql;
+
+select pl_qual_names(42);
+
+drop function pl_qual_names(int);