diff options
Diffstat (limited to 'src/backend/parser/parse_relation.c')
| -rw-r--r-- | src/backend/parser/parse_relation.c | 62 |
1 files changed, 58 insertions, 4 deletions
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c index 14ddd34b76a..fb4ad74edba 100644 --- a/src/backend/parser/parse_relation.c +++ b/src/backend/parser/parse_relation.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.138 2008/10/06 15:15:22 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.139 2008/10/08 01:14:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -215,6 +215,29 @@ scanNameSpaceForCTE(ParseState *pstate, const char *refname, } /* + * Search for a possible "future CTE", that is one that is not yet in scope + * according to the WITH scoping rules. This has nothing to do with valid + * SQL semantics, but it's important for error reporting purposes. + */ +static bool +isFutureCTE(ParseState *pstate, const char *refname) +{ + for (; pstate != NULL; pstate = pstate->parentParseState) + { + ListCell *lc; + + foreach(lc, pstate->p_future_ctes) + { + CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc); + + if (strcmp(cte->ctename, refname) == 0) + return true; + } + } + return false; +} + +/* * searchRangeTable * See if any RangeTblEntry could possibly match the RangeVar. * If so, return a pointer to the RangeTblEntry; else return NULL. @@ -702,8 +725,9 @@ buildScalarFunctionAlias(Node *funcexpr, char *funcname, /* * Open a table during parse analysis * - * This is essentially just the same as heap_openrv(), except that it - * arranges to include the RangeVar's parse location in any resulting error. + * This is essentially just the same as heap_openrv(), except that it caters + * to some parser-specific error reporting needs, notably that it arranges + * to include the RangeVar's parse location in any resulting error. * * Note: properly, lockmode should be declared LOCKMODE not int, but that * would require importing storage/lock.h into parse_relation.h. Since @@ -716,7 +740,37 @@ parserOpenTable(ParseState *pstate, const RangeVar *relation, int lockmode) ParseCallbackState pcbstate; setup_parser_errposition_callback(&pcbstate, pstate, relation->location); - rel = heap_openrv(relation, lockmode); + rel = try_heap_openrv(relation, lockmode); + if (rel == NULL) + { + if (relation->schemaname) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("relation \"%s.%s\" does not exist", + relation->schemaname, relation->relname))); + else + { + /* + * An unqualified name might have been meant as a reference to + * some not-yet-in-scope CTE. The bare "does not exist" message + * has proven remarkably unhelpful for figuring out such problems, + * so we take pains to offer a specific hint. + */ + if (isFutureCTE(pstate, relation->relname)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("relation \"%s\" does not exist", + relation->relname), + errdetail("There is a WITH item named \"%s\", but it cannot be referenced from this part of the query.", + relation->relname), + errhint("Use WITH RECURSIVE, or re-order the WITH items to remove forward references."))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_TABLE), + errmsg("relation \"%s\" does not exist", + relation->relname))); + } + } cancel_parser_errposition_callback(&pcbstate); return rel; } |