Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit3437286

Browse files
committed
Modify the parser's error reporting to include a specific hint for the case
of referencing a WITH item that's not yet in scope according to the SQLspec's semantics. This seems to be an easy error to make, and the bare"relation doesn't exist" message doesn't lead one's mind in the correctdirection to fix it.
1 parente229998 commit3437286

File tree

5 files changed

+146
-9
lines changed

5 files changed

+146
-9
lines changed

‎src/backend/access/heap/heapam.c

Lines changed: 71 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.264 2008/09/30 10:52:10 heikki Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.265 2008/10/08 01:14:44 tgl Exp $
1212
*
1313
*
1414
* INTERFACE ROUTINES
@@ -1016,6 +1016,45 @@ relation_openrv(const RangeVar *relation, LOCKMODE lockmode)
10161016
returnrelation_open(relOid,lockmode);
10171017
}
10181018

1019+
/* ----------------
1020+
*try_relation_openrv - open any relation specified by a RangeVar
1021+
*
1022+
*Same as relation_openrv, but return NULL instead of failing for
1023+
*relation-not-found. (Note that some other causes, such as
1024+
*permissions problems, will still result in an ereport.)
1025+
* ----------------
1026+
*/
1027+
Relation
1028+
try_relation_openrv(constRangeVar*relation,LOCKMODElockmode)
1029+
{
1030+
OidrelOid;
1031+
1032+
/*
1033+
* Check for shared-cache-inval messages before trying to open the
1034+
* relation. This is needed to cover the case where the name identifies a
1035+
* rel that has been dropped and recreated since the start of our
1036+
* transaction: if we don't flush the old syscache entry then we'll latch
1037+
* onto that entry and suffer an error when we do RelationIdGetRelation.
1038+
* Note that relation_open does not need to do this, since a relation's
1039+
* OID never changes.
1040+
*
1041+
* We skip this if asked for NoLock, on the assumption that the caller has
1042+
* already ensured some appropriate lock is held.
1043+
*/
1044+
if (lockmode!=NoLock)
1045+
AcceptInvalidationMessages();
1046+
1047+
/* Look up the appropriate relation using namespace search */
1048+
relOid=RangeVarGetRelid(relation, true);
1049+
1050+
/* Return NULL on not-found */
1051+
if (!OidIsValid(relOid))
1052+
returnNULL;
1053+
1054+
/* Let relation_open do the rest */
1055+
returnrelation_open(relOid,lockmode);
1056+
}
1057+
10191058
/* ----------------
10201059
*relation_close - close any relation
10211060
*
@@ -1097,6 +1136,37 @@ heap_openrv(const RangeVar *relation, LOCKMODE lockmode)
10971136
returnr;
10981137
}
10991138

1139+
/* ----------------
1140+
*try_heap_openrv - open a heap relation specified
1141+
*by a RangeVar node
1142+
*
1143+
*As above, but return NULL instead of failing for relation-not-found.
1144+
* ----------------
1145+
*/
1146+
Relation
1147+
try_heap_openrv(constRangeVar*relation,LOCKMODElockmode)
1148+
{
1149+
Relationr;
1150+
1151+
r=try_relation_openrv(relation,lockmode);
1152+
1153+
if (r)
1154+
{
1155+
if (r->rd_rel->relkind==RELKIND_INDEX)
1156+
ereport(ERROR,
1157+
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
1158+
errmsg("\"%s\" is an index",
1159+
RelationGetRelationName(r))));
1160+
elseif (r->rd_rel->relkind==RELKIND_COMPOSITE_TYPE)
1161+
ereport(ERROR,
1162+
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
1163+
errmsg("\"%s\" is a composite type",
1164+
RelationGetRelationName(r))));
1165+
}
1166+
1167+
returnr;
1168+
}
1169+
11001170

11011171
/* ----------------
11021172
*heap_beginscan- begin relation scan

‎src/backend/parser/parse_cte.c

Lines changed: 9 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/parser/parse_cte.c,v 2.3 2008/10/07 19:27:04 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/parser/parse_cte.c,v 2.4 2008/10/08 01:14:44 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -108,6 +108,7 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
108108

109109
/* Only one WITH clause per query level */
110110
Assert(pstate->p_ctenamespace==NIL);
111+
Assert(pstate->p_future_ctes==NIL);
111112

112113
/*
113114
* For either type of WITH, there must not be duplicate CTE names in
@@ -216,14 +217,20 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
216217
/*
217218
* For non-recursive WITH, just analyze each CTE in sequence and then
218219
* add it to the ctenamespace. This corresponds to the spec's
219-
* definition of the scope of each WITH name.
220+
* definition of the scope of each WITH name. However, to allow
221+
* error reports to be aware of the possibility of an erroneous
222+
* reference, we maintain a list in p_future_ctes of the
223+
* not-yet-visible CTEs.
220224
*/
225+
pstate->p_future_ctes=list_copy(withClause->ctes);
226+
221227
foreach(lc,withClause->ctes)
222228
{
223229
CommonTableExpr*cte= (CommonTableExpr*)lfirst(lc);
224230

225231
analyzeCTE(pstate,cte);
226232
pstate->p_ctenamespace=lappend(pstate->p_ctenamespace,cte);
233+
pstate->p_future_ctes=list_delete_first(pstate->p_future_ctes);
227234
}
228235
}
229236

‎src/backend/parser/parse_relation.c

Lines changed: 58 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.138 2008/10/06 15:15:22 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.139 2008/10/08 01:14:44 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -214,6 +214,29 @@ scanNameSpaceForCTE(ParseState *pstate, const char *refname,
214214
returnNULL;
215215
}
216216

217+
/*
218+
* Search for a possible "future CTE", that is one that is not yet in scope
219+
* according to the WITH scoping rules. This has nothing to do with valid
220+
* SQL semantics, but it's important for error reporting purposes.
221+
*/
222+
staticbool
223+
isFutureCTE(ParseState*pstate,constchar*refname)
224+
{
225+
for (;pstate!=NULL;pstate=pstate->parentParseState)
226+
{
227+
ListCell*lc;
228+
229+
foreach(lc,pstate->p_future_ctes)
230+
{
231+
CommonTableExpr*cte= (CommonTableExpr*)lfirst(lc);
232+
233+
if (strcmp(cte->ctename,refname)==0)
234+
return true;
235+
}
236+
}
237+
return false;
238+
}
239+
217240
/*
218241
* searchRangeTable
219242
* See if any RangeTblEntry could possibly match the RangeVar.
@@ -702,8 +725,9 @@ buildScalarFunctionAlias(Node *funcexpr, char *funcname,
702725
/*
703726
* Open a table during parse analysis
704727
*
705-
* This is essentially just the same as heap_openrv(), except that it
706-
* arranges to include the RangeVar's parse location in any resulting error.
728+
* This is essentially just the same as heap_openrv(), except that it caters
729+
* to some parser-specific error reporting needs, notably that it arranges
730+
* to include the RangeVar's parse location in any resulting error.
707731
*
708732
* Note: properly, lockmode should be declared LOCKMODE not int, but that
709733
* would require importing storage/lock.h into parse_relation.h. Since
@@ -716,7 +740,37 @@ parserOpenTable(ParseState *pstate, const RangeVar *relation, int lockmode)
716740
ParseCallbackStatepcbstate;
717741

718742
setup_parser_errposition_callback(&pcbstate,pstate,relation->location);
719-
rel=heap_openrv(relation,lockmode);
743+
rel=try_heap_openrv(relation,lockmode);
744+
if (rel==NULL)
745+
{
746+
if (relation->schemaname)
747+
ereport(ERROR,
748+
(errcode(ERRCODE_UNDEFINED_TABLE),
749+
errmsg("relation \"%s.%s\" does not exist",
750+
relation->schemaname,relation->relname)));
751+
else
752+
{
753+
/*
754+
* An unqualified name might have been meant as a reference to
755+
* some not-yet-in-scope CTE. The bare "does not exist" message
756+
* has proven remarkably unhelpful for figuring out such problems,
757+
* so we take pains to offer a specific hint.
758+
*/
759+
if (isFutureCTE(pstate,relation->relname))
760+
ereport(ERROR,
761+
(errcode(ERRCODE_UNDEFINED_TABLE),
762+
errmsg("relation \"%s\" does not exist",
763+
relation->relname),
764+
errdetail("There is a WITH item named \"%s\", but it cannot be referenced from this part of the query.",
765+
relation->relname),
766+
errhint("Use WITH RECURSIVE, or re-order the WITH items to remove forward references.")));
767+
else
768+
ereport(ERROR,
769+
(errcode(ERRCODE_UNDEFINED_TABLE),
770+
errmsg("relation \"%s\" does not exist",
771+
relation->relname)));
772+
}
773+
}
720774
cancel_parser_errposition_callback(&pcbstate);
721775
returnrel;
722776
}

‎src/include/access/heapam.h

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.138 2008/08/11 11:05:11 heikki Exp $
10+
* $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.139 2008/10/08 01:14:44 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -45,10 +45,12 @@ extern Relation relation_open(Oid relationId, LOCKMODE lockmode);
4545
externRelationtry_relation_open(OidrelationId,LOCKMODElockmode);
4646
externRelationrelation_open_nowait(OidrelationId,LOCKMODElockmode);
4747
externRelationrelation_openrv(constRangeVar*relation,LOCKMODElockmode);
48+
externRelationtry_relation_openrv(constRangeVar*relation,LOCKMODElockmode);
4849
externvoidrelation_close(Relationrelation,LOCKMODElockmode);
4950

5051
externRelationheap_open(OidrelationId,LOCKMODElockmode);
5152
externRelationheap_openrv(constRangeVar*relation,LOCKMODElockmode);
53+
externRelationtry_heap_openrv(constRangeVar*relation,LOCKMODElockmode);
5254

5355
#defineheap_close(r,l) relation_close(r,l)
5456

‎src/include/parser/parse_node.h

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.57 2008/10/04 21:56:55 tgl Exp $
10+
* $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.58 2008/10/08 01:14:44 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -54,6 +54,9 @@
5454
* at the moment. This is different from p_relnamespace because you have
5555
* to make an RTE before you can access a CTE.
5656
*
57+
* p_future_ctes: list of CommonTableExprs (WITH items) that are not yet
58+
* visible due to scope rules. This is used to help improve error messages.
59+
*
5760
* p_paramtypes: an array of p_numparams type OIDs for $n parameter symbols
5861
* (zeroth entry in array corresponds to $1). If p_variableparams is true, the
5962
* set of param types is not predetermined; in that case, a zero array entry
@@ -73,6 +76,7 @@ typedef struct ParseState
7376
List*p_relnamespace;/* current namespace for relations */
7477
List*p_varnamespace;/* current namespace for columns */
7578
List*p_ctenamespace;/* current namespace for common table exprs */
79+
List*p_future_ctes;/* common table exprs not yet in namespace */
7680
Oid*p_paramtypes;/* OIDs of types for $n parameter symbols */
7781
intp_numparams;/* allocated size of p_paramtypes[] */
7882
intp_next_resno;/* next targetlist resno to assign */

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp