allow referring to functions without arguments when unique
Started by Peter Eisentrautalmost 9 years ago6 messages
This is the "grand finale" that goes on top of the "DROP FUNCTION of
multiple functions" patch set. The purpose is to allow referring to
functions without having to spell out the argument list, when the
function name is unique. This is especially useful when having to
operate on "business logic" functions with many many arguments. It's an
SQL standard feature, and it applies everywhere a function is referred
to in the grammar. We already have the lookup logic for the regproc
type, and thanks to the grand refactoring of the parser representation
of functions, this is quite a small patch. There is a bit of
reduce/reduce parser mystery, to keep the reviewer entertained. (The
equivalent could be implemented for aggregates and operators, but I
haven't done that here yet.)
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachments:
0001-Allow-referring-to-functions-without-arguments-when-.patchtext/x-patch; name=0001-Allow-referring-to-functions-without-arguments-when-.patchDownload
From 40eeb753abc83bbb0e38997fb518f9cd663f1729 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Sat, 25 Feb 2017 19:13:15 -0500
Subject: [PATCH] Allow referring to functions without arguments when unique
In DDL commands referring to an existing function, allow omitting the
argument list if the function name is unique in its schema, per SQL
standard.
This uses the same logic that the regproc type uses for finding
functions by name only.
---
doc/src/sgml/ref/alter_extension.sgml | 2 +-
doc/src/sgml/ref/alter_function.sgml | 13 ++++++------
doc/src/sgml/ref/alter_opfamily.sgml | 7 ++++---
doc/src/sgml/ref/comment.sgml | 2 +-
doc/src/sgml/ref/create_cast.sgml | 6 ++++--
doc/src/sgml/ref/create_transform.sgml | 12 +++++++----
doc/src/sgml/ref/drop_function.sgml | 26 ++++++++++++++++++++----
doc/src/sgml/ref/grant.sgml | 2 +-
doc/src/sgml/ref/revoke.sgml | 2 +-
doc/src/sgml/ref/security_label.sgml | 2 +-
src/backend/nodes/copyfuncs.c | 1 +
src/backend/nodes/equalfuncs.c | 1 +
src/backend/parser/gram.y | 27 +++++++++++++++++++++++++
src/backend/parser/parse_func.c | 17 +++++++++++++++-
src/include/nodes/parsenodes.h | 3 +++
src/test/regress/expected/create_function_3.out | 9 ++++++++-
src/test/regress/sql/create_function_3.sql | 7 +++++++
17 files changed, 113 insertions(+), 26 deletions(-)
diff --git a/doc/src/sgml/ref/alter_extension.sgml b/doc/src/sgml/ref/alter_extension.sgml
index de6d6dca16..a7c0927d1c 100644
--- a/doc/src/sgml/ref/alter_extension.sgml
+++ b/doc/src/sgml/ref/alter_extension.sgml
@@ -39,7 +39,7 @@
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN DATA WRAPPER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable> |
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
OPERATOR <replaceable class="PARAMETER">operator_name</replaceable> (<replaceable class="PARAMETER">left_type</replaceable>, <replaceable class="PARAMETER">right_type</replaceable>) |
OPERATOR CLASS <replaceable class="PARAMETER">object_name</replaceable> USING <replaceable class="parameter">index_method</replaceable> |
diff --git a/doc/src/sgml/ref/alter_function.sgml b/doc/src/sgml/ref/alter_function.sgml
index 0388d06b95..168eeb7c52 100644
--- a/doc/src/sgml/ref/alter_function.sgml
+++ b/doc/src/sgml/ref/alter_function.sgml
@@ -21,15 +21,15 @@
<refsynopsisdiv>
<synopsis>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
<replaceable class="PARAMETER">action</replaceable> [ ... ] [ RESTRICT ]
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
RENAME TO <replaceable>new_name</replaceable>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
SET SCHEMA <replaceable>new_schema</replaceable>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
DEPENDS ON EXTENSION <replaceable>extension_name</replaceable>
<phrase>where <replaceable class="PARAMETER">action</replaceable> is one of:</phrase>
@@ -75,7 +75,8 @@ <title>Parameters</title>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of an existing function.
+ The name (optionally schema-qualified) of an existing function. If no
+ argument list is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/alter_opfamily.sgml b/doc/src/sgml/ref/alter_opfamily.sgml
index 4511c7f7b2..0bafe5b8f8 100644
--- a/doc/src/sgml/ref/alter_opfamily.sgml
+++ b/doc/src/sgml/ref/alter_opfamily.sgml
@@ -25,7 +25,7 @@
{ OPERATOR <replaceable class="parameter">strategy_number</replaceable> <replaceable class="parameter">operator_name</replaceable> ( <replaceable class="parameter">op_type</replaceable>, <replaceable class="parameter">op_type</replaceable> )
[ FOR SEARCH | FOR ORDER BY <replaceable class="parameter">sort_family_name</replaceable> ]
| FUNCTION <replaceable class="parameter">support_number</replaceable> [ ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) ]
- <replaceable class="parameter">function_name</replaceable> ( <replaceable class="parameter">argument_type</replaceable> [, ...] )
+ <replaceable class="parameter">function_name</replaceable> [ ( <replaceable class="parameter">argument_type</replaceable> [, ...] ) ]
} [, ... ]
ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> DROP
@@ -195,8 +195,9 @@ <title>Parameters</title>
<term><replaceable class="parameter">function_name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of a function that is an
- index method support procedure for the operator family.
+ The name (optionally schema-qualified) of a function that is an index
+ method support procedure for the operator family. If no argument list
+ is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index c1cf587cb2..7483c8c03f 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -37,7 +37,7 @@
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN DATA WRAPPER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable> |
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
INDEX <replaceable class="PARAMETER">object_name</replaceable> |
LARGE OBJECT <replaceable class="PARAMETER">large_object_oid</replaceable> |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
diff --git a/doc/src/sgml/ref/create_cast.sgml b/doc/src/sgml/ref/create_cast.sgml
index 11266755e5..a7d13edc22 100644
--- a/doc/src/sgml/ref/create_cast.sgml
+++ b/doc/src/sgml/ref/create_cast.sgml
@@ -19,7 +19,7 @@
<refsynopsisdiv>
<synopsis>
CREATE CAST (<replaceable>source_type</replaceable> AS <replaceable>target_type</replaceable>)
- WITH FUNCTION <replaceable>function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...])
+ WITH FUNCTION <replaceable>function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ]
[ AS ASSIGNMENT | AS IMPLICIT ]
CREATE CAST (<replaceable>source_type</replaceable> AS <replaceable>target_type</replaceable>)
@@ -192,7 +192,7 @@ <title>Parameters</title>
</varlistentry>
<varlistentry>
- <term><replaceable>function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -200,6 +200,8 @@ <title>Parameters</title>
be schema-qualified. If it is not, the function will be looked
up in the schema search path. The function's result data type must
match the target type of the cast. Its arguments are discussed below.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_transform.sgml b/doc/src/sgml/ref/create_transform.sgml
index f44ee89d33..647c3b9f05 100644
--- a/doc/src/sgml/ref/create_transform.sgml
+++ b/doc/src/sgml/ref/create_transform.sgml
@@ -19,8 +19,8 @@
<refsynopsisdiv>
<synopsis>
CREATE [ OR REPLACE ] TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> (
- FROM SQL WITH FUNCTION <replaceable>from_sql_function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...]),
- TO SQL WITH FUNCTION <replaceable>to_sql_function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...])
+ FROM SQL WITH FUNCTION <replaceable>from_sql_function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ],
+ TO SQL WITH FUNCTION <replaceable>to_sql_function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ]
);
</synopsis>
</refsynopsisdiv>
@@ -104,7 +104,7 @@ <title>Parameters</title>
</varlistentry>
<varlistentry>
- <term><replaceable>from_sql_function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>from_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -116,12 +116,14 @@ <title>Parameters</title>
SQL-level function returning <type>internal</type> without at
least one argument of type <type>internal</type>.) The actual return
value will be something specific to the language implementation.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><replaceable>to_sql_function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>to_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -130,6 +132,8 @@ <title>Parameters</title>
<type>internal</type> and return the type that is the type for the
transform. The actual argument value will be something specific to the
language implementation.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/drop_function.sgml b/doc/src/sgml/ref/drop_function.sgml
index 5969b084b4..44446e2fac 100644
--- a/doc/src/sgml/ref/drop_function.sgml
+++ b/doc/src/sgml/ref/drop_function.sgml
@@ -21,7 +21,7 @@
<refsynopsisdiv>
<synopsis>
-DROP FUNCTION [ IF EXISTS ] <replaceable class="parameter">name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) [, ...]
+DROP FUNCTION [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] [, ...]
[ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -56,7 +56,8 @@ <title>Parameters</title>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of an existing function.
+ The name (optionally schema-qualified) of an existing function. If no
+ argument list is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
@@ -141,14 +142,31 @@ <title>Examples</title>
<programlisting>
DROP FUNCTION sqrt(integer), sqrt(bigint);
</programlisting></para>
+
+ <para>
+ If the function name is unique in its schema, it can be referred to without
+ an argument list:
+<programlisting>
+DROP FUNCTION update_employee_salaries;
+</programlisting>
+ Note that this is different from
+<programlisting>
+DROP FUNCTION update_employee_salaries();
+</programlisting>
+ which refers to a function with zero arguments, whereas the first variant
+ can refer to a function with any number of arguments, including zero, as
+ long as the name is unique.
+ </para>
</refsect1>
<refsect1 id="SQL-DROPFUNCTION-compatibility">
<title>Compatibility</title>
<para>
- A <command>DROP FUNCTION</command> statement is defined in the SQL
- standard, but it is not compatible with this command.
+ This command conforms to the SQL standard, except that the standard only
+ allows one function to be dropped per command, and apart from the
+ <literal>IF EXISTS</> option and the ability to specify argument modes and
+ names, which are all <productname>PostgreSQL</> extension.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index d8ca39f869..9fb4c2fd7e 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -55,7 +55,7 @@
TO <replaceable class="PARAMETER">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
GRANT { EXECUTE | ALL [ PRIVILEGES ] }
- ON { FUNCTION <replaceable>function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) [, ...]
+ ON { FUNCTION <replaceable>function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) ] [, ...]
| ALL FUNCTIONS IN SCHEMA <replaceable class="PARAMETER">schema_name</replaceable> [, ...] }
TO <replaceable class="PARAMETER">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index fc00129620..ce532543f0 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -70,7 +70,7 @@
REVOKE [ GRANT OPTION FOR ]
{ EXECUTE | ALL [ PRIVILEGES ] }
- ON { FUNCTION <replaceable>function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) [, ...]
+ ON { FUNCTION <replaceable>function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) ] [, ...]
| ALL FUNCTIONS IN SCHEMA <replaceable>schema_name</replaceable> [, ...] }
FROM { [ GROUP ] <replaceable class="PARAMETER">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index 998fe3b7c0..afd86aff3a 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -30,7 +30,7 @@
DOMAIN <replaceable class="PARAMETER">object_name</replaceable> |
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable>
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
LARGE OBJECT <replaceable class="PARAMETER">large_object_oid</replaceable> |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
[ PROCEDURAL ] LANGUAGE <replaceable class="PARAMETER">object_name</replaceable> |
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index bb2a8a3586..3612b9be2f 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2961,6 +2961,7 @@ _copyObjectWithArgs(const ObjectWithArgs *from)
COPY_NODE_FIELD(objname);
COPY_NODE_FIELD(objargs);
+ COPY_SCALAR_FIELD(args_unspecified);
return newnode;
}
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 9fa83b9453..ae6e334ff2 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1099,6 +1099,7 @@ _equalObjectWithArgs(const ObjectWithArgs *a, const ObjectWithArgs *b)
{
COMPARE_NODE_FIELD(objname);
COMPARE_NODE_FIELD(objargs);
+ COMPARE_SCALAR_FIELD(args_unspecified);
return true;
}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index ec07056617..738397bc7c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -7198,6 +7198,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
+ /*
+ * Because of reduce/reduce conflicts, we can't use func_name
+ * below, but we can write it out the long way, which actually
+ * allows more cases.
+ */
+ | type_func_name_keyword
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString(pstrdup($1)));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString($1));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId indirection
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = check_func_name(lcons(makeString($1), $2),
+ yyscanner);
+ n->args_unspecified = true;
+ $$ = n;
+ }
;
/*
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dd9749f205..06bcc99893 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -1914,6 +1914,21 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false, noError);
+ /*
+ * If no arguments were specified, the name must yield a unique candidate.
+ */
+ if (nargs == -1 && clist)
+ {
+ if (clist->next)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_FUNCTION),
+ errmsg("function name \"%s\" is not unique",
+ NameListToString(funcname)),
+ errhint("Specify the argument list to select the function unambiguously.")));
+ else
+ return clist->oid;
+ }
+
while (clist)
{
if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0)
@@ -1962,7 +1977,7 @@ LookupFuncWithArgs(ObjectWithArgs *func, bool noError)
args_item = lnext(args_item);
}
- return LookupFuncName(func->objname, argcount, argoids, noError);
+ return LookupFuncName(func->objname, func->args_unspecified ? -1 : argcount, argoids, noError);
}
/*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 956f99830c..83e92821a4 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1772,6 +1772,9 @@ typedef struct ObjectWithArgs
NodeTag type;
List *objname; /* qualified name of function/operator */
List *objargs; /* list of Typename nodes */
+ bool args_unspecified; /* argument list was omitted, so name must
+ * be unique (note that objargs == NIL means
+ * zero args) */
} ObjectWithArgs;
/*
diff --git a/src/test/regress/expected/create_function_3.out b/src/test/regress/expected/create_function_3.out
index cc4e98a1d4..c85230b93a 100644
--- a/src/test/regress/expected/create_function_3.out
+++ b/src/test/regress/expected/create_function_3.out
@@ -218,13 +218,19 @@ SELECT routine_name, ordinal_position, parameter_name, parameter_default
(7 rows)
DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
+-- overload
+CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
+ IMMUTABLE AS 'SELECT $1 > 0';
+DROP FUNCTION functest_b_1;
+DROP FUNCTION functest_b_2; -- error, ambiguous
+ERROR: function name "functest_b_2" is not unique
+HINT: Specify the argument list to select the function unambiguously.
-- Cleanups
DROP SCHEMA temp_func_test CASCADE;
NOTICE: drop cascades to 16 other objects
DETAIL: drop cascades to function functest_a_1(text,date)
drop cascades to function functest_a_2(text[])
drop cascades to function functest_a_3()
-drop cascades to function functest_b_1(integer)
drop cascades to function functest_b_2(integer)
drop cascades to function functest_b_3(integer)
drop cascades to function functest_b_4(integer)
@@ -237,5 +243,6 @@ drop cascades to function functext_f_1(integer)
drop cascades to function functext_f_2(integer)
drop cascades to function functext_f_3(integer)
drop cascades to function functext_f_4(integer)
+drop cascades to function functest_b_2(bigint)
DROP USER regress_unpriv_user;
RESET search_path;
diff --git a/src/test/regress/sql/create_function_3.sql b/src/test/regress/sql/create_function_3.sql
index 66a463b089..1c0623ba7f 100644
--- a/src/test/regress/sql/create_function_3.sql
+++ b/src/test/regress/sql/create_function_3.sql
@@ -158,6 +158,13 @@ CREATE FUNCTION functest_IS_3(a int default 1, out b int)
DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
+-- overload
+CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
+ IMMUTABLE AS 'SELECT $1 > 0';
+
+DROP FUNCTION functest_b_1;
+DROP FUNCTION functest_b_2; -- error, ambiguous
+
-- Cleanups
DROP SCHEMA temp_func_test CASCADE;
--
2.12.0
Re: allow referring to functions without arguments when unique
On Wed, Mar 1, 2017 at 11:50 AM, Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
This is the "grand finale" that goes on top of the "DROP FUNCTION of
multiple functions" patch set. The purpose is to allow referring to
functions without having to spell out the argument list, when the
function name is unique. This is especially useful when having to
operate on "business logic" functions with many many arguments. It's an
SQL standard feature, and it applies everywhere a function is referred
to in the grammar. We already have the lookup logic for the regproc
type, and thanks to the grand refactoring of the parser representation
of functions, this is quite a small patch. There is a bit of
reduce/reduce parser mystery, to keep the reviewer entertained.
... Which would be nice.
(The
equivalent could be implemented for aggregates and operators, but I
haven't done that here yet.)
OK. After a lookup, I am just seeing opfamily, opclass missing, so
this patch is doing it as you describe.
I have read through the code once, still I am waiting for the DROP
FUNCTION patches to be committed before doing a real hands-on.
@@ -7198,6 +7198,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
This may not have arguments listed, so is function_with_argtypes really adapted?
+ /*
+ * If no arguments were specified, the name must yield a unique candidate.
+ */
+ if (nargs == -1 && clist)
+ {
+ if (clist->next)
+ ereport(ERROR,
I would have used list_length here for clarity.--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -1914,6 +1914,21 @@ LookupFuncName(List *funcname, int nargs, const
Oid *argtypes, bool noError)
The comment at the top of LookupFuncName() needs a refresh. The caller
can as well just use a function name without arguments.
--
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Re: allow referring to functions without arguments when unique
On Fri, Mar 3, 2017 at 4:12 PM, Michael Paquier
<michael.paquier@gmail.com> wrote:
On Wed, Mar 1, 2017 at 11:50 AM, Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:This is the "grand finale" that goes on top of the "DROP FUNCTION of
multiple functions" patch set. The purpose is to allow referring to
functions without having to spell out the argument list, when the
function name is unique. This is especially useful when having to
operate on "business logic" functions with many many arguments. It's an
SQL standard feature, and it applies everywhere a function is referred
to in the grammar. We already have the lookup logic for the regproc
type, and thanks to the grand refactoring of the parser representation
of functions, this is quite a small patch. There is a bit of
reduce/reduce parser mystery, to keep the reviewer entertained.... Which would be nice.
(The
equivalent could be implemented for aggregates and operators, but I
haven't done that here yet.)OK. After a lookup, I am just seeing opfamily, opclass missing, so
this patch is doing it as you describe.I have read through the code once, still I am waiting for the DROP
FUNCTION patches to be committed before doing a real hands-on.@@ -7198,6 +7198,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
This may not have arguments listed, so is function_with_argtypes really adapted?+ /* + * If no arguments were specified, the name must yield a unique candidate. + */ + if (nargs == -1 && clist) + { + if (clist->next) + ereport(ERROR, I would have used list_length here for clarity.--- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -1914,6 +1914,21 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError) The comment at the top of LookupFuncName() needs a refresh. The caller can as well just use a function name without arguments.
+ /*
+ * Because of reduce/reduce conflicts, we can't use func_name
+ * below, but we can write it out the long way, which actually
+ * allows more cases.
+ */
+ | type_func_name_keyword
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString(pstrdup($1)));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString($1));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId indirection
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = check_func_name(lcons(makeString($1), $2),
+ yyscanner);
+ n->args_unspecified = true;
+ $$ = n;
+ }
I have spent some time looking at this one. Another solution would be
to extend func_args to make the difference between an empty list and a
list with no arguments. This would need an intermediate structure for
parsing, and it does not seem worth the cost so I am fine with this
solution.=# create schema popo;
CREATE SCHEMA
=# CREATE FUNCTION popo.dup2(int,int) RETURNS TABLE(f1 int, f2 text)
AS $$ SELECT
$1, CAST($1 AS text) || ' is text' $$
LANGUAGE SQL;
CREATE FUNCTION
=# CREATE FUNCTION dup2(int,int) RETURNS TABLE(f1 int, f2 text)
AS $$ SELECT
$1, CAST($1 AS text) || ' is text' $$
LANGUAGE SQL;
CREATE FUNCTION
=# set search_path to 'public,popo';
SET
Time: 0.463 ms
=# drop function dup2;
ERROR: 42883: function dup2() does not exist
LOCATION: LookupFuncName, parse_func.c:1944
In this case I would have expected an error telling that the name is
ambiguous. FuncnameGetCandidates() returns an empty list.
--
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Re: allow referring to functions without arguments when unique
On 3/7/17 00:32, Michael Paquier wrote:
OK. After a lookup, I am just seeing opfamily, opclass missing, so
this patch is doing it as you describe.
I'm not sure what you mean here.
@@ -7198,6 +7198,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
This may not have arguments listed, so is function_with_argtypes really adapted?
Well, we could do something like function_with_opt_argtypes?
+ /* + * If no arguments were specified, the name must yield a unique candidate. + */ + if (nargs == -1 && clist) + { + if (clist->next) + ereport(ERROR, I would have used list_length here for clarity.
This is actually not a "List" node.
The comment at the top of LookupFuncName() needs a refresh. The caller
can as well just use a function name without arguments.
Fixed.
=# set search_path to 'public,popo';
I think you mean
set search_path to public,popo;
=# drop function dup2;
ERROR: 42883: function dup2() does not exist
LOCATION: LookupFuncName, parse_func.c:1944
In this case I would have expected an error telling that the name is
ambiguous. FuncnameGetCandidates() returns an empty list.
Your example works correctly if you set the schema path correctly.
However, the error message is misleading with the parentheses. I have
updated that to create a different error message for this case, and
added a test case.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachments:
v2-0001-Allow-referring-to-functions-without-arguments-wh.patchapplication/x-patch; name=v2-0001-Allow-referring-to-functions-without-arguments-wh.patchDownload
From ac83b6f71433d2101f67dd148a4af2aac78129ee Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Thu, 9 Mar 2017 23:58:48 -0500
Subject: [PATCH v2] Allow referring to functions without arguments when unique
In DDL commands referring to an existing function, allow omitting the
argument list if the function name is unique in its schema, per SQL
standard.
This uses the same logic that the regproc type uses for finding
functions by name only.
---
doc/src/sgml/ref/alter_extension.sgml | 2 +-
doc/src/sgml/ref/alter_function.sgml | 13 +++++----
doc/src/sgml/ref/alter_opfamily.sgml | 7 +++--
doc/src/sgml/ref/comment.sgml | 2 +-
doc/src/sgml/ref/create_cast.sgml | 6 ++--
doc/src/sgml/ref/create_transform.sgml | 12 +++++---
doc/src/sgml/ref/drop_function.sgml | 35 ++++++++++++++++++++---
doc/src/sgml/ref/grant.sgml | 2 +-
doc/src/sgml/ref/revoke.sgml | 2 +-
doc/src/sgml/ref/security_label.sgml | 2 +-
src/backend/nodes/copyfuncs.c | 1 +
src/backend/nodes/equalfuncs.c | 1 +
src/backend/parser/gram.y | 27 ++++++++++++++++++
src/backend/parser/parse_func.c | 37 +++++++++++++++++++++++--
src/include/nodes/parsenodes.h | 3 ++
src/test/regress/expected/create_function_3.out | 11 +++++++-
src/test/regress/sql/create_function_3.sql | 8 ++++++
17 files changed, 143 insertions(+), 28 deletions(-)
diff --git a/doc/src/sgml/ref/alter_extension.sgml b/doc/src/sgml/ref/alter_extension.sgml
index de6d6dca16..a7c0927d1c 100644
--- a/doc/src/sgml/ref/alter_extension.sgml
+++ b/doc/src/sgml/ref/alter_extension.sgml
@@ -39,7 +39,7 @@
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN DATA WRAPPER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable> |
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
OPERATOR <replaceable class="PARAMETER">operator_name</replaceable> (<replaceable class="PARAMETER">left_type</replaceable>, <replaceable class="PARAMETER">right_type</replaceable>) |
OPERATOR CLASS <replaceable class="PARAMETER">object_name</replaceable> USING <replaceable class="parameter">index_method</replaceable> |
diff --git a/doc/src/sgml/ref/alter_function.sgml b/doc/src/sgml/ref/alter_function.sgml
index 0388d06b95..168eeb7c52 100644
--- a/doc/src/sgml/ref/alter_function.sgml
+++ b/doc/src/sgml/ref/alter_function.sgml
@@ -21,15 +21,15 @@
<refsynopsisdiv>
<synopsis>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
<replaceable class="PARAMETER">action</replaceable> [ ... ] [ RESTRICT ]
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
RENAME TO <replaceable>new_name</replaceable>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
SET SCHEMA <replaceable>new_schema</replaceable>
-ALTER FUNCTION <replaceable>name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] )
+ALTER FUNCTION <replaceable>name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ]
DEPENDS ON EXTENSION <replaceable>extension_name</replaceable>
<phrase>where <replaceable class="PARAMETER">action</replaceable> is one of:</phrase>
@@ -75,7 +75,8 @@ <title>Parameters</title>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of an existing function.
+ The name (optionally schema-qualified) of an existing function. If no
+ argument list is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/alter_opfamily.sgml b/doc/src/sgml/ref/alter_opfamily.sgml
index 4511c7f7b2..0bafe5b8f8 100644
--- a/doc/src/sgml/ref/alter_opfamily.sgml
+++ b/doc/src/sgml/ref/alter_opfamily.sgml
@@ -25,7 +25,7 @@
{ OPERATOR <replaceable class="parameter">strategy_number</replaceable> <replaceable class="parameter">operator_name</replaceable> ( <replaceable class="parameter">op_type</replaceable>, <replaceable class="parameter">op_type</replaceable> )
[ FOR SEARCH | FOR ORDER BY <replaceable class="parameter">sort_family_name</replaceable> ]
| FUNCTION <replaceable class="parameter">support_number</replaceable> [ ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) ]
- <replaceable class="parameter">function_name</replaceable> ( <replaceable class="parameter">argument_type</replaceable> [, ...] )
+ <replaceable class="parameter">function_name</replaceable> [ ( <replaceable class="parameter">argument_type</replaceable> [, ...] ) ]
} [, ... ]
ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> DROP
@@ -195,8 +195,9 @@ <title>Parameters</title>
<term><replaceable class="parameter">function_name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of a function that is an
- index method support procedure for the operator family.
+ The name (optionally schema-qualified) of a function that is an index
+ method support procedure for the operator family. If no argument list
+ is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index c1cf587cb2..7483c8c03f 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -37,7 +37,7 @@
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN DATA WRAPPER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable> |
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
INDEX <replaceable class="PARAMETER">object_name</replaceable> |
LARGE OBJECT <replaceable class="PARAMETER">large_object_oid</replaceable> |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
diff --git a/doc/src/sgml/ref/create_cast.sgml b/doc/src/sgml/ref/create_cast.sgml
index 11266755e5..a7d13edc22 100644
--- a/doc/src/sgml/ref/create_cast.sgml
+++ b/doc/src/sgml/ref/create_cast.sgml
@@ -19,7 +19,7 @@
<refsynopsisdiv>
<synopsis>
CREATE CAST (<replaceable>source_type</replaceable> AS <replaceable>target_type</replaceable>)
- WITH FUNCTION <replaceable>function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...])
+ WITH FUNCTION <replaceable>function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ]
[ AS ASSIGNMENT | AS IMPLICIT ]
CREATE CAST (<replaceable>source_type</replaceable> AS <replaceable>target_type</replaceable>)
@@ -192,7 +192,7 @@ <title>Parameters</title>
</varlistentry>
<varlistentry>
- <term><replaceable>function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -200,6 +200,8 @@ <title>Parameters</title>
be schema-qualified. If it is not, the function will be looked
up in the schema search path. The function's result data type must
match the target type of the cast. Its arguments are discussed below.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_transform.sgml b/doc/src/sgml/ref/create_transform.sgml
index f44ee89d33..647c3b9f05 100644
--- a/doc/src/sgml/ref/create_transform.sgml
+++ b/doc/src/sgml/ref/create_transform.sgml
@@ -19,8 +19,8 @@
<refsynopsisdiv>
<synopsis>
CREATE [ OR REPLACE ] TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> (
- FROM SQL WITH FUNCTION <replaceable>from_sql_function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...]),
- TO SQL WITH FUNCTION <replaceable>to_sql_function_name</replaceable> (<replaceable>argument_type</replaceable> [, ...])
+ FROM SQL WITH FUNCTION <replaceable>from_sql_function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ],
+ TO SQL WITH FUNCTION <replaceable>to_sql_function_name</replaceable> [ (<replaceable>argument_type</replaceable> [, ...]) ]
);
</synopsis>
</refsynopsisdiv>
@@ -104,7 +104,7 @@ <title>Parameters</title>
</varlistentry>
<varlistentry>
- <term><replaceable>from_sql_function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>from_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -116,12 +116,14 @@ <title>Parameters</title>
SQL-level function returning <type>internal</type> without at
least one argument of type <type>internal</type>.) The actual return
value will be something specific to the language implementation.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><replaceable>to_sql_function_name</replaceable>(<replaceable>argument_type</replaceable> [, ...])</term>
+ <term><literal><replaceable>to_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>
<listitem>
<para>
@@ -130,6 +132,8 @@ <title>Parameters</title>
<type>internal</type> and return the type that is the type for the
transform. The actual argument value will be something specific to the
language implementation.
+ If no argument list is specified, the function name must be unique in
+ its schema.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/drop_function.sgml b/doc/src/sgml/ref/drop_function.sgml
index 5969b084b4..0aa984528d 100644
--- a/doc/src/sgml/ref/drop_function.sgml
+++ b/doc/src/sgml/ref/drop_function.sgml
@@ -21,7 +21,7 @@
<refsynopsisdiv>
<synopsis>
-DROP FUNCTION [ IF EXISTS ] <replaceable class="parameter">name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) [, ...]
+DROP FUNCTION [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] [, ...]
[ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -56,7 +56,8 @@ <title>Parameters</title>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
- The name (optionally schema-qualified) of an existing function.
+ The name (optionally schema-qualified) of an existing function. If no
+ argument list is specified, the name must be unique in its schema.
</para>
</listitem>
</varlistentry>
@@ -141,14 +142,40 @@ <title>Examples</title>
<programlisting>
DROP FUNCTION sqrt(integer), sqrt(bigint);
</programlisting></para>
+
+ <para>
+ If the function name is unique in its schema, it can be referred to without
+ an argument list:
+<programlisting>
+DROP FUNCTION update_employee_salaries;
+</programlisting>
+ Note that this is different from
+<programlisting>
+DROP FUNCTION update_employee_salaries();
+</programlisting>
+ which refers to a function with zero arguments, whereas the first variant
+ can refer to a function with any number of arguments, including zero, as
+ long as the name is unique.
+ </para>
</refsect1>
<refsect1 id="SQL-DROPFUNCTION-compatibility">
<title>Compatibility</title>
<para>
- A <command>DROP FUNCTION</command> statement is defined in the SQL
- standard, but it is not compatible with this command.
+ This command conforms to the SQL standard, with
+ these <productname>PostgreSQL</productname> extensions:
+ <itemizedlist>
+ <listitem>
+ <para>The standard only allows one function to be dropped per command.</para>
+ </listitem>
+ <listitem>
+ <para>The <literal>IF EXISTS</literal> option</para>
+ </listitem>
+ <listitem>
+ <para>The ability to specify argument modes and names</para>
+ </listitem>
+ </itemizedlist>
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index d8ca39f869..9fb4c2fd7e 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -55,7 +55,7 @@
TO <replaceable class="PARAMETER">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
GRANT { EXECUTE | ALL [ PRIVILEGES ] }
- ON { FUNCTION <replaceable>function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) [, ...]
+ ON { FUNCTION <replaceable>function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) ] [, ...]
| ALL FUNCTIONS IN SCHEMA <replaceable class="PARAMETER">schema_name</replaceable> [, ...] }
TO <replaceable class="PARAMETER">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index fc00129620..ce532543f0 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -70,7 +70,7 @@
REVOKE [ GRANT OPTION FOR ]
{ EXECUTE | ALL [ PRIVILEGES ] }
- ON { FUNCTION <replaceable>function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) [, ...]
+ ON { FUNCTION <replaceable>function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">arg_name</replaceable> ] <replaceable class="parameter">arg_type</replaceable> [, ...] ] ) ] [, ...]
| ALL FUNCTIONS IN SCHEMA <replaceable>schema_name</replaceable> [, ...] }
FROM { [ GROUP ] <replaceable class="PARAMETER">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index 998fe3b7c0..afd86aff3a 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -30,7 +30,7 @@
DOMAIN <replaceable class="PARAMETER">object_name</replaceable> |
EVENT TRIGGER <replaceable class="PARAMETER">object_name</replaceable> |
FOREIGN TABLE <replaceable class="PARAMETER">object_name</replaceable>
- FUNCTION <replaceable class="PARAMETER">function_name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) |
+ FUNCTION <replaceable class="PARAMETER">function_name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] |
LARGE OBJECT <replaceable class="PARAMETER">large_object_oid</replaceable> |
MATERIALIZED VIEW <replaceable class="PARAMETER">object_name</replaceable> |
[ PROCEDURAL ] LANGUAGE <replaceable class="PARAMETER">object_name</replaceable> |
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index bfc2ac1716..25fd051d6e 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3067,6 +3067,7 @@ _copyObjectWithArgs(const ObjectWithArgs *from)
COPY_NODE_FIELD(objname);
COPY_NODE_FIELD(objargs);
+ COPY_SCALAR_FIELD(args_unspecified);
return newnode;
}
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 54e9c983a0..67529e3f86 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1119,6 +1119,7 @@ _equalObjectWithArgs(const ObjectWithArgs *a, const ObjectWithArgs *b)
{
COMPARE_NODE_FIELD(objname);
COMPARE_NODE_FIELD(objargs);
+ COMPARE_SCALAR_FIELD(args_unspecified);
return true;
}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index e7acc2d9a2..6316688a88 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -7202,6 +7202,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
+ /*
+ * Because of reduce/reduce conflicts, we can't use func_name
+ * below, but we can write it out the long way, which actually
+ * allows more cases.
+ */
+ | type_func_name_keyword
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString(pstrdup($1)));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = list_make1(makeString($1));
+ n->args_unspecified = true;
+ $$ = n;
+ }
+ | ColId indirection
+ {
+ ObjectWithArgs *n = makeNode(ObjectWithArgs);
+ n->objname = check_func_name(lcons(makeString($1), $2),
+ yyscanner);
+ n->args_unspecified = true;
+ $$ = n;
+ }
;
/*
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dd9749f205..55853c20bb 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -1895,8 +1895,10 @@ func_signature_string(List *funcname, int nargs,
/*
* LookupFuncName
- * Given a possibly-qualified function name and a set of argument types,
- * look up the function.
+ *
+ * Given a possibly-qualified function name and optionally a set of argument
+ * types, look up the function. Pass nargs == -1 to indicate that no argument
+ * types are specified.
*
* If the function name is not schema-qualified, it is sought in the current
* namespace search path.
@@ -1914,6 +1916,35 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false, noError);
+ /*
+ * If no arguments were specified, the name must yield a unique candidate.
+ */
+ if (nargs == -1)
+ {
+ if (clist)
+ {
+ if (clist->next)
+ {
+ if (!noError)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_FUNCTION),
+ errmsg("function name \"%s\" is not unique",
+ NameListToString(funcname)),
+ errhint("Specify the argument list to select the function unambiguously.")));
+ }
+ else
+ return clist->oid;
+ }
+ else
+ {
+ if (!noError)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not find a function named \"%s\"",
+ NameListToString(funcname))));
+ }
+ }
+
while (clist)
{
if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0)
@@ -1962,7 +1993,7 @@ LookupFuncWithArgs(ObjectWithArgs *func, bool noError)
args_item = lnext(args_item);
}
- return LookupFuncName(func->objname, argcount, argoids, noError);
+ return LookupFuncName(func->objname, func->args_unspecified ? -1 : argcount, argoids, noError);
}
/*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index a44d2178e1..d576523f6a 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1811,6 +1811,9 @@ typedef struct ObjectWithArgs
NodeTag type;
List *objname; /* qualified name of function/operator */
List *objargs; /* list of Typename nodes */
+ bool args_unspecified; /* argument list was omitted, so name must
+ * be unique (note that objargs == NIL means
+ * zero args) */
} ObjectWithArgs;
/*
diff --git a/src/test/regress/expected/create_function_3.out b/src/test/regress/expected/create_function_3.out
index cc4e98a1d4..b5e19485e5 100644
--- a/src/test/regress/expected/create_function_3.out
+++ b/src/test/regress/expected/create_function_3.out
@@ -218,13 +218,21 @@ SELECT routine_name, ordinal_position, parameter_name, parameter_default
(7 rows)
DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
+-- overload
+CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
+ IMMUTABLE AS 'SELECT $1 > 0';
+DROP FUNCTION functest_b_1;
+DROP FUNCTION functest_b_1; -- error, not found
+ERROR: could not find a function named "functest_b_1"
+DROP FUNCTION functest_b_2; -- error, ambiguous
+ERROR: function name "functest_b_2" is not unique
+HINT: Specify the argument list to select the function unambiguously.
-- Cleanups
DROP SCHEMA temp_func_test CASCADE;
NOTICE: drop cascades to 16 other objects
DETAIL: drop cascades to function functest_a_1(text,date)
drop cascades to function functest_a_2(text[])
drop cascades to function functest_a_3()
-drop cascades to function functest_b_1(integer)
drop cascades to function functest_b_2(integer)
drop cascades to function functest_b_3(integer)
drop cascades to function functest_b_4(integer)
@@ -237,5 +245,6 @@ drop cascades to function functext_f_1(integer)
drop cascades to function functext_f_2(integer)
drop cascades to function functext_f_3(integer)
drop cascades to function functext_f_4(integer)
+drop cascades to function functest_b_2(bigint)
DROP USER regress_unpriv_user;
RESET search_path;
diff --git a/src/test/regress/sql/create_function_3.sql b/src/test/regress/sql/create_function_3.sql
index 66a463b089..0a0e407aab 100644
--- a/src/test/regress/sql/create_function_3.sql
+++ b/src/test/regress/sql/create_function_3.sql
@@ -158,6 +158,14 @@ CREATE FUNCTION functest_IS_3(a int default 1, out b int)
DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
+-- overload
+CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
+ IMMUTABLE AS 'SELECT $1 > 0';
+
+DROP FUNCTION functest_b_1;
+DROP FUNCTION functest_b_1; -- error, not found
+DROP FUNCTION functest_b_2; -- error, ambiguous
+
-- Cleanups
DROP SCHEMA temp_func_test CASCADE;
--
2.12.0
Re: allow referring to functions without arguments when unique
On Fri, Mar 10, 2017 at 2:03 PM, Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
On 3/7/17 00:32, Michael Paquier wrote:
@@ -7198,6 +7198,33 @@ function_with_argtypes:
n->objargs = extractArgTypes($2);
$$ = n;
}
This may not have arguments listed, so is function_with_argtypes really adapted?Well, we could do something like function_with_opt_argtypes?
I don't have a good idea about this name, so let's just keep it as-is...
The comment at the top of LookupFuncName() needs a refresh. The caller
can as well just use a function name without arguments.Fixed.
=# set search_path to 'public,popo';
I think you mean
set search_path to public,popo;
Thanks. Right.
=# drop function dup2;
ERROR: 42883: function dup2() does not exist
LOCATION: LookupFuncName, parse_func.c:1944
In this case I would have expected an error telling that the name is
ambiguous. FuncnameGetCandidates() returns an empty list.Your example works correctly if you set the schema path correctly.
However, the error message is misleading with the parentheses. I have
updated that to create a different error message for this case, and
added a test case.
+ {
+ if (!noError)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not find a function named \"%s\"",
+ NameListToString(funcname))));
+ }Finally found out what I was looking for in the comments at the top of
FuncnameGetCandidates():
* We search a single namespace if the function name is qualified, else
* all namespaces in the search path. In the multiple-namespace case,
* we arrange for entries in earlier namespaces to mask identical entries in
* later namespaces.
And this correctly matches what your patch is doing, aka only the
first function found is removed and the next ones are discarded.
This looks good to me, so switched as ready for committer.
--
Michael
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Re: allow referring to functions without arguments when unique
On 3/14/17 03:03, Michael Paquier wrote:
This looks good to me, so switched as ready for committer.
committed
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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