-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.230 2009/10/03 23:10:47 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.231 2009/10/21 20:22:38 tgl Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
<variablelist>
- <varlistentry id="guc-add-missing-from" xreflabel="add_missing_from">
- <term><varname>add_missing_from</varname> (<type>boolean</type>)</term>
- <indexterm><primary>FROM</><secondary>missing</></>
- <indexterm>
- <primary><varname>add_missing_from</> configuration parameter</primary>
- </indexterm>
- <listitem>
- <para>
- When on, tables that are referenced by a query will be
- automatically added to the <literal>FROM</> clause if not
- already present. This behavior does not comply with the SQL
- standard and many people dislike it because it can mask mistakes
- (such as referencing a table where you should have referenced
- its alias). The default is <literal>off</>. This variable can be
- enabled for compatibility with releases of
- <productname>PostgreSQL</> prior to 8.1, where this behavior was
- allowed by default.
- </para>
-
- <para>
- Note that even when this variable is enabled, a warning
- message will be emitted for each implicit <literal>FROM</>
- entry referenced by a query. Users are encouraged to update
- their applications to not rely on this behavior, by adding all
- tables referenced by a query to the query's <literal>FROM</>
- clause (or its <literal>USING</> clause in the case of
- <command>DELETE</>).
- </para>
- </listitem>
- </varlistentry>
-
<varlistentry id="guc-array-nulls" xreflabel="array_nulls">
<term><varname>array_nulls</varname> (<type>boolean</type>)</term>
<indexterm>
-<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.55 2009/06/17 21:58:49 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.56 2009/10/21 20:22:38 tgl Exp $ -->
<chapter id="queries">
<title>Queries</title>
</para>
<para>
- The alias becomes the new name of the table reference for the
- current query — it is no longer possible to refer to the table
- by the original name. Thus:
+ The alias becomes the new name of the table reference so far as the
+ current query is concerned — it is not allowed to refer to the
+ table by the original name elsewhere in the query. Thus, this is not
+ valid:
<programlisting>
-SELECT * FROM my_table AS m WHERE my_table.a > 5;
+SELECT * FROM my_table AS m WHERE my_table.a > 5; -- wrong
</programlisting>
- is not valid according to the SQL standard. In
- <productname>PostgreSQL</productname> this will draw an error, assuming the
- <xref linkend="guc-add-missing-from"> configuration variable is
- <literal>off</> (as it is by default). If it is <literal>on</>,
- an implicit table reference will be added to the
- <literal>FROM</literal> clause, so the query is processed as if
- it were written as:
-<programlisting>
-SELECT * FROM my_table AS m, my_table AS my_table WHERE my_table.a > 5;
-</programlisting>
- That will result in a cross join, which is usually not what you want.
</para>
<para>
<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.125 2009/09/18 05:00:42 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.126 2009/10/21 20:22:38 tgl Exp $
PostgreSQL documentation
-->
<productname>PostgreSQL</productname> releases prior to
8.1 would accept queries of this form, and add an implicit entry
to the query's <literal>FROM</literal> clause for each table
- referenced by the query. This is no longer the default behavior,
- because it does not comply with the SQL standard, and is
- considered by many to be error-prone. For compatibility with
- applications that rely on this behavior the <xref
- linkend="guc-add-missing-from"> configuration variable can be
- enabled.
+ referenced by the query. This is no longer allowed.
</para>
</refsect2>
<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/show.sgml,v 1.47 2008/11/14 10:22:47 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/show.sgml,v 1.48 2009/10/21 20:22:38 tgl Exp $
PostgreSQL documentation
-->
Show all settings:
<programlisting>
SHOW ALL;
- name | setting | description
---------------------------------+--------------------------------+----------------------------------------------------------------------------------------------
- add_missing_from | off | Automatically adds missing table references to FROM clauses.
- allow_system_table_mods | off | Allows modifications of the structure of system tables.
+ name | setting | description
+---------------------------------+-------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------
+ allow_system_table_mods | off | Allows modifications of the structure of system tables.
.
.
.
- work_mem | 1024 | Sets the maximum memory to be used for query workspaces.
- zero_damaged_pages | off | Continues processing past damaged page headers.
-(146 rows)
+ xmloption | content | Sets whether XML data in implicit parsing and serialization operations is to be considered as documents or content fragments.
+ zero_damaged_pages | off | Continues processing past damaged page headers.
+(196 rows)
</programlisting>
</para>
</refsect1>
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.244 2009/10/08 02:39:23 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.245 2009/10/21 20:22:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
name2 = strVal(field2);
/* Try to identify as a once-qualified column */
- node = qualifiedNameToVar(pstate, NULL, name1, name2, true,
+ node = qualifiedNameToVar(pstate, NULL, name1, name2,
cref->location);
if (node == NULL)
{
/*
* Not known as a column of any range-table entry, so try
- * it as a function call. Here, we will create an
- * implicit RTE for tables not already entered.
+ * it as a function call.
*/
node = transformWholeRowRef(pstate, NULL, name1,
cref->location);
name3 = strVal(field3);
/* Try to identify as a twice-qualified column */
- node = qualifiedNameToVar(pstate, name1, name2, name3, true,
+ node = qualifiedNameToVar(pstate, name1, name2, name3,
cref->location);
if (node == NULL)
{
name4 = strVal(field4);
/* Try to identify as a twice-qualified column */
- node = qualifiedNameToVar(pstate, name2, name3, name4, true,
+ node = qualifiedNameToVar(pstate, name2, name3, name4,
cref->location);
if (node == NULL)
{
int sublevels_up;
Oid toid;
- /* Look up the referenced RTE, creating it if needed */
+ /* Look up the referenced RTE, failing if not present */
rte = refnameRangeTblEntry(pstate, schemaname, relname, location,
&sublevels_up);
if (rte == NULL)
- rte = addImplicitRTE(pstate,
- makeRangeVar(schemaname, relname, location));
+ errorMissingRTE(pstate,
+ makeRangeVar(schemaname, relname, location));
vnum = RTERangeTablePosn(pstate, rte, &sublevels_up);
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.143 2009/07/16 06:33:43 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.144 2009/10/21 20:22:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/syscache.h"
-/* GUC parameter */
-bool add_missing_from;
-
static RangeTblEntry *scanNameSpaceForRefname(ParseState *pstate,
const char *refname, int location);
static RangeTblEntry *scanNameSpaceForRelid(ParseState *pstate, Oid relid,
int location, bool include_dropped,
List **colnames, List **colvars);
static int specialAttNum(const char *attname);
-static void warnAutoRange(ParseState *pstate, RangeVar *relation);
/*
* visible in the p_relnamespace lists. This behavior is invalid per the SQL
* spec, and it may give ambiguous results (there might be multiple equally
* valid matches, but only one will be returned). This must be used ONLY
- * as a heuristic in giving suitable error messages. See warnAutoRange.
+ * as a heuristic in giving suitable error messages. See errorMissingRTE.
*
* Notice that we consider both matches on actual relation (or CTE) name
* and matches on alias.
char *schemaname,
char *refname,
char *colname,
- bool implicitRTEOK,
int location)
{
RangeTblEntry *rte;
rte = refnameRangeTblEntry(pstate, schemaname, refname, location,
&sublevels_up);
-
if (rte == NULL)
- {
- if (!implicitRTEOK)
- return NULL;
- rte = addImplicitRTE(pstate,
- makeRangeVar(schemaname, refname, location));
- }
+ return NULL;
return scanRTEForColumn(pstate, rte, colname, location);
}
}
/*
- * Add a POSTQUEL-style implicit RTE.
- *
- * We assume caller has already checked that there is no RTE or join with
- * a conflicting name.
- */
-RangeTblEntry *
-addImplicitRTE(ParseState *pstate, RangeVar *relation)
-{
- CommonTableExpr *cte = NULL;
- Index levelsup = 0;
- RangeTblEntry *rte;
-
- /* issue warning or error as needed */
- warnAutoRange(pstate, relation);
-
- /* if it is an unqualified name, it might be a CTE reference */
- if (!relation->schemaname)
- cte = scanNameSpaceForCTE(pstate, relation->relname, &levelsup);
-
- /*
- * Note that we set inFromCl true, so that the RTE will be listed
- * explicitly if the parsetree is ever decompiled by ruleutils.c. This
- * provides a migration path for views/rules that were originally written
- * with implicit-RTE syntax.
- */
- if (cte)
- rte = addRangeTableEntryForCTE(pstate, cte, levelsup, NULL, true);
- else
- rte = addRangeTableEntry(pstate, relation, NULL, false, true);
- /* Add to joinlist and relnamespace, but not varnamespace */
- addRTEtoQuery(pstate, rte, true, true, false);
-
- return rte;
-}
-
-/*
* expandRTE -- expand the columns of a rangetable entry
*
* This creates lists of an RTE's column names (aliases if provided, else
}
/*
- * Generate a warning or error about an implicit RTE, if appropriate.
+ * Generate a suitable error about a missing RTE.
*
- * If ADD_MISSING_FROM is not enabled, raise an error. Otherwise, emit
- * a warning.
+ * Since this is a very common type of error, we work rather hard to
+ * produce a helpful message.
*/
-static void
-warnAutoRange(ParseState *pstate, RangeVar *relation)
+void
+errorMissingRTE(ParseState *pstate, RangeVar *relation)
{
RangeTblEntry *rte;
int sublevels_up;
/*
* Check to see if there are any potential matches in the query's
- * rangetable. This affects the message we provide.
+ * rangetable.
*/
rte = searchRangeTable(pstate, relation);
&sublevels_up) == rte)
badAlias = rte->eref->aliasname;
- if (!add_missing_from)
- {
- if (rte)
- ereport(ERROR,
- (errcode(ERRCODE_UNDEFINED_TABLE),
- errmsg("invalid reference to FROM-clause entry for table \"%s\"",
- relation->relname),
- (badAlias ?
- errhint("Perhaps you meant to reference the table alias \"%s\".",
- badAlias) :
- errhint("There is an entry for table \"%s\", but it cannot be referenced from this part of the query.",
- rte->eref->aliasname)),
- parser_errposition(pstate, relation->location)));
- else
- ereport(ERROR,
- (errcode(ERRCODE_UNDEFINED_TABLE),
- errmsg("missing FROM-clause entry for table \"%s\"",
- relation->relname),
- parser_errposition(pstate, relation->location)));
- }
- else
- {
- /* just issue a warning */
- ereport(NOTICE,
+ if (rte)
+ ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_TABLE),
- errmsg("adding missing FROM-clause entry for table \"%s\"",
+ errmsg("invalid reference to FROM-clause entry for table \"%s\"",
relation->relname),
(badAlias ?
- errhint("Perhaps you meant to reference the table alias \"%s\".",
- badAlias) :
- (rte ?
- errhint("There is an entry for table \"%s\", but it cannot be referenced from this part of the query.",
- rte->eref->aliasname) : 0)),
+ errhint("Perhaps you meant to reference the table alias \"%s\".",
+ badAlias) :
+ errhint("There is an entry for table \"%s\", but it cannot be referenced from this part of the query.",
+ rte->eref->aliasname)),
+ parser_errposition(pstate, relation->location)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_TABLE),
+ errmsg("missing FROM-clause entry for table \"%s\"",
+ relation->relname),
parser_errposition(pstate, relation->location)));
- }
}
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.172 2009/07/16 06:33:43 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.173 2009/10/21 20:22:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
rte = refnameRangeTblEntry(pstate, schemaname, relname, cref->location,
&sublevels_up);
if (rte == NULL)
- rte = addImplicitRTE(pstate,
- makeRangeVar(schemaname, relname,
- cref->location));
+ errorMissingRTE(pstate,
+ makeRangeVar(schemaname, relname, cref->location));
rtindex = RTERangeTablePosn(pstate, rte, &sublevels_up);
*
* tlist entries are generated for each relation appearing in the query's
* varnamespace. We do not consider relnamespace because that would include
- * input tables of aliasless JOINs, NEW/OLD pseudo-entries, implicit RTEs,
- * etc.
+ * input tables of aliasless JOINs, NEW/OLD pseudo-entries, etc.
*
* The referenced relations/columns are marked as requiring SELECT access.
*/
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.521 2009/10/13 14:18:40 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.522 2009/10/21 20:22:38 tgl Exp $
*
*--------------------------------------------------------------------
*/
#include "optimizer/paths.h"
#include "optimizer/planmain.h"
#include "parser/parse_expr.h"
-#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parser.h"
#include "parser/scansup.h"
false, assign_transaction_read_only, NULL
},
{
- {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
- gettext_noop("Automatically adds missing table references to FROM clauses."),
- NULL
- },
- &add_missing_from,
- false, NULL, NULL
- },
- {
{"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Check function bodies during CREATE FUNCTION."),
NULL
# - Previous PostgreSQL Versions -
-#add_missing_from = off
#array_nulls = on
#backslash_quote = safe_encoding # on, off, or safe_encoding
#default_with_oids = off
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.63 2009/09/09 03:32:52 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.64 2009/10/21 20:22:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* This is different from p_relnamespace because a JOIN without an alias does
* not hide the contained tables (so they must still be in p_relnamespace)
* but it does hide their columns (unqualified references to the columns must
- * refer to the JOIN, not the member tables). Also, we put POSTQUEL-style
- * implicit RTEs into p_relnamespace but not p_varnamespace, so that they
- * do not affect the set of columns available for unqualified references.
+ * refer to the JOIN, not the member tables). Other special RTEs such as
+ * NEW/OLD for rules may also appear in just one of these lists.
*
* p_ctenamespace: list of CommonTableExprs (WITH items) that are visible
* at the moment. This is different from p_relnamespace because you have
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/parser/parse_relation.h,v 1.64 2009/06/11 14:49:11 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_relation.h,v 1.65 2009/10/21 20:22:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "parser/parse_node.h"
-extern bool add_missing_from;
-
extern RangeTblEntry *refnameRangeTblEntry(ParseState *pstate,
const char *schemaname,
const char *refname,
char *schemaname,
char *refname,
char *colname,
- bool implicitRTEOK,
int location);
extern void markVarForSelectPriv(ParseState *pstate, Var *var,
RangeTblEntry *rte);
extern void addRTEtoQuery(ParseState *pstate, RangeTblEntry *rte,
bool addToJoinList,
bool addToRelNameSpace, bool addToVarNameSpace);
-extern RangeTblEntry *addImplicitRTE(ParseState *pstate, RangeVar *relation);
+extern void errorMissingRTE(ParseState *pstate, RangeVar *relation);
extern void expandRTE(RangeTblEntry *rte, int rtindex, int sublevels_up,
int location, bool include_dropped,
List **colnames, List **colvars);
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"
LINE 1: DELETE FROM delete_test dt WHERE delete_test.a > 25;
^
HINT: Perhaps you meant to reference the table alias "dt".
-ROLLBACK;
SELECT * FROM delete_test;
id | a
----+----
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"
LINE 1: select f1, q.c1 from quadtable;
^
-rollback;
select f1, (q).c1, (qq.q).c1.i from quadtable qq;
f1 | c1 | i
----+-----------+-----
^
-- 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"
LINE 1: UPDATE update_test AS t SET b = update_test.b + 10 WHERE t.a...
^
HINT: Perhaps you meant to reference the table alias "t".
-ROLLBACK;
DROP TABLE update_test;
-- 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
+DROP TABLE delete_test;
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;
-- 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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