From 1d763d9107eda2db054d0f7edee4c2e9b55dfacf Mon Sep 17 00:00:00 2001
From: Neil Conway <neilc@samurai.com>
Date: Sun, 22 Jan 2006 05:20:35 +0000
Subject: [PATCH] Allow an optional alias for the target table to be specified
for UPDATE and DELETE. If specified, the alias must be used instead of the
full table name. Also, the alias currently cannot be used in the SET clause
of UPDATE.
Patch from Atsushi Ogawa, various editorialization by Neil Conway.
Along the way, make the rowtypes regression test pass if add_missing_from
is enabled, and add a new (skeletal) regression test for DELETE.
---
doc/src/sgml/ref/delete.sgml | 17 ++++++++++++++--
doc/src/sgml/ref/update.sgml | 20 +++++++++++++++++--
doc/src/sgml/regress.sgml | 4 ++--
src/backend/parser/gram.y | 22 ++++++++++++++++++---
src/backend/parser/parse_clause.c | 4 ++--
src/test/regress/expected/delete.out | 27 ++++++++++++++++++++++++++
src/test/regress/expected/rowtypes.out | 3 +++
src/test/regress/expected/update.out | 25 ++++++++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/serial_schedule | 3 ++-
src/test/regress/sql/delete.sql | 22 +++++++++++++++++++++
src/test/regress/sql/rowtypes.sql | 3 +++
src/test/regress/sql/update.sql | 16 +++++++++++++++
13 files changed, 155 insertions(+), 13 deletions(-)
create mode 100644 src/test/regress/expected/delete.out
create mode 100644 src/test/regress/sql/delete.sql
diff --git a/doc/src/sgml/ref/delete.sgml b/doc/src/sgml/ref/delete.sgml
index 8369d991372..b61e6cacd21 100644
--- a/doc/src/sgml/ref/delete.sgml
+++ b/doc/src/sgml/ref/delete.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/delete.sgml,v 1.25 2005/11/01 21:09:50 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/delete.sgml,v 1.26 2006/01/22 05:20:33 neilc Exp $
PostgreSQL documentation
-->
@@ -20,7 +20,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DELETE FROM [ ONLY ] <replaceable class="PARAMETER">table</replaceable>
+DELETE FROM [ ONLY ] <replaceable class="PARAMETER">table</replaceable> [ [ AS ] <replaceable class="parameter">alias</replaceable> ]
[ USING <replaceable class="PARAMETER">usinglist</replaceable> ]
[ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
</synopsis>
@@ -91,6 +91,19 @@ DELETE FROM [ ONLY ] <replaceable class="PARAMETER">table</replaceable>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">alias</replaceable></term>
+ <listitem>
+ <para>
+ A substitute name for the target table. When an alias is
+ provided, it completely hides the actual name of the table. For
+ example, given <literal>DELETE FROM foo AS f</>, the remainder
+ of the <command>DELETE</command> statement must refer to this
+ table as <literal>f</> not <literal>foo</>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="PARAMETER">usinglist</replaceable></term>
<listitem>
diff --git a/doc/src/sgml/ref/update.sgml b/doc/src/sgml/ref/update.sgml
index 503f41de12b..95e4310ab42 100644
--- a/doc/src/sgml/ref/update.sgml
+++ b/doc/src/sgml/ref/update.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/update.sgml,v 1.34 2006/01/19 23:09:42 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/update.sgml,v 1.35 2006/01/22 05:20:33 neilc Exp $
PostgreSQL documentation
-->
@@ -20,7 +20,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replaceable class="PARAMETER">column</replaceable> = { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...]
+UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> [ [ AS ] <replaceable class="parameter">alias</replaceable> ]
+ SET <replaceable class="PARAMETER">column</replaceable> = { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...]
[ FROM <replaceable class="PARAMETER">fromlist</replaceable> ]
[ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
</synopsis>
@@ -73,6 +74,21 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">alias</replaceable></term>
+ <listitem>
+ <para>
+ A substitute name for the target table. When an alias is
+ provided, it completely hides the actual name of the table. For
+ example, given <literal>UPDATE foo AS f</>, the remainder of the
+ <command>UPDATE</command> statement must refer to this table as
+ <literal>f</> not <literal>foo</>. You cannot use the alias in
+ the <literal>SET</literal> clause. For example, <literal>SET
+ f.col = 1</> is invalid.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="PARAMETER">column</replaceable></term>
<listitem>
diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml
index 05749a3157b..11f9468860f 100644
--- a/doc/src/sgml/regress.sgml
+++ b/doc/src/sgml/regress.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.49 2005/10/18 21:43:33 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.50 2006/01/22 05:20:32 neilc Exp $ -->
<chapter id="regress">
<title id="regress-title">Regression Tests</title>
@@ -49,7 +49,7 @@ gmake check
<screen>
<computeroutput>
======================
- All 98 tests passed.
+ All 100 tests passed.
======================
</computeroutput>
</screen>
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 41b22d811c9..22e20165b96 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.522 2006/01/21 02:16:19 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.523 2006/01/22 05:20:33 neilc Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -291,6 +291,7 @@ static void doNegateFloat(Value *v);
%type <node> table_ref
%type <jexpr> joined_table
%type <range> relation_expr
+%type <range> relation_expr_opt_alias
%type <target> target_el insert_target_el update_target_el insert_column_item
%type <typnam> Typename SimpleTypename ConstTypename
@@ -5148,7 +5149,8 @@ insert_column_item:
*
*****************************************************************************/
-DeleteStmt: DELETE_P FROM relation_expr using_clause where_clause
+DeleteStmt: DELETE_P FROM relation_expr_opt_alias
+ using_clause where_clause
{
DeleteStmt *n = makeNode(DeleteStmt);
n->relation = $3;
@@ -5200,7 +5202,7 @@ opt_nowait: NOWAIT { $$ = TRUE; }
*
*****************************************************************************/
-UpdateStmt: UPDATE relation_expr
+UpdateStmt: UPDATE relation_expr_opt_alias
SET update_target_list
from_clause
where_clause
@@ -5878,6 +5880,20 @@ relation_expr:
;
+relation_expr_opt_alias: relation_expr
+ {
+ $$ = $1;
+ }
+ | relation_expr opt_as IDENT
+ {
+ Alias *alias = makeNode(Alias);
+ alias->aliasname = $3;
+ $1->alias = alias;
+ $$ = $1;
+ }
+ ;
+
+
func_table: func_expr { $$ = $1; }
;
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index aee45f3d205..934802e16ec 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.144 2005/11/22 18:17:16 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.145 2006/01/22 05:20:34 neilc Exp $
*
*-------------------------------------------------------------------------
*/
@@ -160,7 +160,7 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
* Now build an RTE.
*/
rte = addRangeTableEntryForRelation(pstate, pstate->p_target_relation,
- NULL, inh, false);
+ relation->alias, inh, false);
pstate->p_target_rangetblentry = rte;
/* assume new rte is at end */
diff --git a/src/test/regress/expected/delete.out b/src/test/regress/expected/delete.out
new file mode 100644
index 00000000000..68128f69d09
--- /dev/null
+++ b/src/test/regress/expected/delete.out
@@ -0,0 +1,27 @@
+CREATE TABLE delete_test (
+ id SERIAL PRIMARY KEY,
+ a INT
+);
+NOTICE: CREATE TABLE will create implicit sequence "delete_test_id_seq" for serial column "delete_test.id"
+NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "delete_test_pkey" for table "delete_test"
+INSERT INTO delete_test (a) VALUES (10);
+INSERT INTO delete_test (a) VALUES (50);
+INSERT INTO delete_test (a) VALUES (100);
+-- allow an alias to be specified for DELETE's target table
+DELETE FROM delete_test AS dt WHERE dt.a > 75;
+-- if an alias is specified, don't allow the original table name
+-- to be referenced
+BEGIN;
+SET LOCAL add_missing_from = false;
+DELETE FROM delete_test dt WHERE delete_test.a > 25;
+ERROR: invalid reference to FROM-clause entry for table "delete_test"
+HINT: Perhaps you meant to reference the table alias "dt".
+ROLLBACK;
+SELECT * FROM delete_test;
+ id | a
+----+----
+ 1 | 10
+ 2 | 50
+(2 rows)
+
+DROP TABLE delete_test;
diff --git a/src/test/regress/expected/rowtypes.out b/src/test/regress/expected/rowtypes.out
index fc46dd14e19..c6b1bfac398 100644
--- a/src/test/regress/expected/rowtypes.out
+++ b/src/test/regress/expected/rowtypes.out
@@ -59,8 +59,11 @@ select * from quadtable;
2 | ("(,4.4)","(5.5,6.6)")
(2 rows)
+begin;
+set local add_missing_from = false;
select f1, q.c1 from quadtable; -- fails, q is a table reference
ERROR: missing FROM-clause entry for table "q"
+rollback;
select f1, (q).c1, (qq.q).c1.i from quadtable qq;
f1 | c1 | i
----+-----------+-----
diff --git a/src/test/regress/expected/update.out b/src/test/regress/expected/update.out
index 3fca2fb41ac..1ff7c8918f5 100644
--- a/src/test/regress/expected/update.out
+++ b/src/test/regress/expected/update.out
@@ -22,4 +22,29 @@ SELECT * FROM update_test;
10 |
(2 rows)
+-- aliases for the UPDATE target table
+UPDATE update_test AS t SET b = 10 WHERE t.a = 10;
+SELECT * FROM update_test;
+ a | b
+----+----
+ 10 | 10
+ 10 | 10
+(2 rows)
+
+UPDATE update_test t SET b = t.b + 10 WHERE t.a = 10;
+SELECT * FROM update_test;
+ a | b
+----+----
+ 10 | 20
+ 10 | 20
+(2 rows)
+
+-- if an alias for the target table is specified, don't allow references
+-- to the original table name
+BEGIN;
+SET LOCAL add_missing_from = false;
+UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a = 10;
+ERROR: invalid reference to FROM-clause entry for table "update_test"
+HINT: Perhaps you meant to reference the table alias "t".
+ROLLBACK;
DROP TABLE update_test;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index d5777794bfb..fef609711b2 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -60,7 +60,7 @@ ignore: random
# ----------
# The fourth group of parallel test
# ----------
-test: select_into select_distinct select_distinct_on select_implicit select_having subselect union case join aggregates transactions random portals arrays btree_index hash_index update namespace prepared_xacts
+test: select_into select_distinct select_distinct_on select_implicit select_having subselect union case join aggregates transactions random portals arrays btree_index hash_index update namespace prepared_xacts delete
test: privileges
test: misc
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index dd60070433c..3342dc2ba1f 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.29 2005/11/19 17:39:45 adunstan Exp $
+# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.30 2006/01/22 05:20:34 neilc Exp $
# This should probably be in an order similar to parallel_schedule.
test: boolean
test: char
@@ -74,6 +74,7 @@ test: arrays
test: btree_index
test: hash_index
test: update
+test: delete
test: namespace
test: prepared_xacts
test: privileges
diff --git a/src/test/regress/sql/delete.sql b/src/test/regress/sql/delete.sql
new file mode 100644
index 00000000000..86cabfcf648
--- /dev/null
+++ b/src/test/regress/sql/delete.sql
@@ -0,0 +1,22 @@
+CREATE TABLE delete_test (
+ id SERIAL PRIMARY KEY,
+ a INT
+);
+
+INSERT INTO delete_test (a) VALUES (10);
+INSERT INTO delete_test (a) VALUES (50);
+INSERT INTO delete_test (a) VALUES (100);
+
+-- allow an alias to be specified for DELETE's target table
+DELETE FROM delete_test AS dt WHERE dt.a > 75;
+
+-- if an alias is specified, don't allow the original table name
+-- to be referenced
+BEGIN;
+SET LOCAL add_missing_from = false;
+DELETE FROM delete_test dt WHERE delete_test.a > 25;
+ROLLBACK;
+
+SELECT * FROM delete_test;
+
+DROP TABLE delete_test;
\ No newline at end of file
diff --git a/src/test/regress/sql/rowtypes.sql b/src/test/regress/sql/rowtypes.sql
index 613c4e91f91..43d57bc6035 100644
--- a/src/test/regress/sql/rowtypes.sql
+++ b/src/test/regress/sql/rowtypes.sql
@@ -35,7 +35,10 @@ insert into quadtable values (2, ((null,4.4),(5.5,6.6)));
select * from quadtable;
+begin;
+set local add_missing_from = false;
select f1, q.c1 from quadtable; -- fails, q is a table reference
+rollback;
select f1, (q).c1, (qq.q).c1.i from quadtable qq;
diff --git a/src/test/regress/sql/update.sql b/src/test/regress/sql/update.sql
index 577596abb1b..99fd74bca79 100644
--- a/src/test/regress/sql/update.sql
+++ b/src/test/regress/sql/update.sql
@@ -16,4 +16,20 @@ UPDATE update_test SET a = DEFAULT, b = DEFAULT;
SELECT * FROM update_test;
+-- aliases for the UPDATE target table
+UPDATE update_test AS t SET b = 10 WHERE t.a = 10;
+
+SELECT * FROM update_test;
+
+UPDATE update_test t SET b = t.b + 10 WHERE t.a = 10;
+
+SELECT * FROM update_test;
+
+-- if an alias for the target table is specified, don't allow references
+-- to the original table name
+BEGIN;
+SET LOCAL add_missing_from = false;
+UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a = 10;
+ROLLBACK;
+
DROP TABLE update_test;
--
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