diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 96 |
1 files changed, 67 insertions, 29 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 87041d3b6e0..cc849ebf07b 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.67 2000/09/17 22:21:27 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.68 2000/09/29 18:21:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -64,7 +64,7 @@ static bool exprIsInSortList(Node *expr, List *sortList, List *targetList); * POSTQUEL, we allow references to relations not specified in the * from-clause. PostgreSQL keeps this extension to standard SQL.) * - * Note: we assume that pstate's p_rtable and p_jointree lists were + * Note: we assume that pstate's p_rtable and p_joinlist lists were * initialized to NIL when the pstate was created. We will add onto * any entries already present --- this is needed for rule processing! */ @@ -75,7 +75,7 @@ makeRangeTable(ParseState *pstate, List *frmList) /* * The grammar will have produced a list of RangeVars, RangeSubselects, - * and/or JoinExprs. Transform each one, and then add it to the join tree. + * and/or JoinExprs. Transform each one, and then add it to the joinlist. */ foreach(fl, frmList) { @@ -83,7 +83,7 @@ makeRangeTable(ParseState *pstate, List *frmList) List *containedRels; n = transformFromClauseItem(pstate, n, &containedRels); - pstate->p_jointree = lappend(pstate->p_jointree, n); + pstate->p_joinlist = lappend(pstate->p_joinlist, n); } } @@ -92,7 +92,7 @@ makeRangeTable(ParseState *pstate, List *frmList) * Add the target relation of INSERT/UPDATE/DELETE to the range table, * and make the special links to it in the ParseState. * - * inJoinSet says whether to add the target to the join tree. + * inJoinSet says whether to add the target to the join list. * For INSERT, we don't want the target to be joined to; it's a * destination of tuples, not a source. For UPDATE/DELETE, we do * need to scan or join the target. @@ -106,15 +106,32 @@ setTargetTable(ParseState *pstate, char *relname, bool inh, bool inJoinSet) if (refnameRangeTablePosn(pstate, relname, NULL) == 0) { rte = addRangeTableEntry(pstate, relname, NULL, inh, false); + /* + * Since the rel wasn't in the rangetable already, it's not being + * read; override addRangeTableEntry's default checkForRead. + * + * If we find an explicit reference to the rel later during + * parse analysis, scanRTEForColumn will change checkForRead + * to 'true' again. That can't happen for INSERT but it is + * possible for UPDATE and DELETE. + */ + rte->checkForRead = false; } else { rte = refnameRangeTableEntry(pstate, relname); + /* + * Since the rel was in the rangetable already, it's being read + * as well as written. Therefore, leave checkForRead true. + */ /* XXX what if pre-existing entry has wrong inh setting? */ } + /* Mark target table as requiring write access. */ + rte->checkForWrite = true; + if (inJoinSet) - addRTEtoJoinTree(pstate, rte); + addRTEtoJoinList(pstate, rte); /* This could only happen for multi-action rules */ if (pstate->p_target_relation != NULL) @@ -242,22 +259,22 @@ transformJoinOnClause(ParseState *pstate, JoinExpr *j, List *containedRels) { Node *result; - List *sv_jointree; + List *sv_joinlist; List *clause_varnos, *l; /* * This is a tad tricky, for two reasons. First, at the point where * we're called, the two subtrees of the JOIN node aren't yet part of - * the pstate's jointree, which means that transformExpr() won't resolve + * the pstate's joinlist, which means that transformExpr() won't resolve * unqualified references to their columns correctly. We fix this in a - * slightly klugy way: temporarily make the pstate's jointree consist of + * slightly klugy way: temporarily make the pstate's joinlist consist of * just those two subtrees (which creates exactly the namespace the ON * clause should see). This is OK only because the ON clause can't - * legally alter the jointree by causing relation refs to be added. + * legally alter the joinlist by causing relation refs to be added. */ - sv_jointree = pstate->p_jointree; - pstate->p_jointree = lcons(j->larg, lcons(j->rarg, NIL)); + sv_joinlist = pstate->p_joinlist; + pstate->p_joinlist = makeList2(j->larg, j->rarg); /* This part is just like transformWhereClause() */ result = transformExpr(pstate, j->quals, EXPR_COLUMN_FIRST); @@ -267,12 +284,12 @@ transformJoinOnClause(ParseState *pstate, JoinExpr *j, typeidTypeName(exprType(result))); } - pstate->p_jointree = sv_jointree; + pstate->p_joinlist = sv_joinlist; /* * Second, we need to check that the ON condition doesn't refer to any * rels outside the input subtrees of the JOIN. It could do that despite - * our hack on the jointree if it uses fully-qualified names. So, grovel + * our hack on the joinlist if it uses fully-qualified names. So, grovel * through the transformed clause and make sure there are no bogus * references. */ @@ -312,7 +329,7 @@ transformTableEntry(ParseState *pstate, RangeVar *r) rte = addRangeTableEntry(pstate, relname, r->name, r->inh, true); /* - * We create a RangeTblRef, but we do not add it to the jointree here. + * We create a RangeTblRef, but we do not add it to the joinlist here. * makeRangeTable will do so, if we are at top level of the FROM clause. */ rtr = makeNode(RangeTblRef); @@ -333,6 +350,16 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) SelectStmt *subquery = (SelectStmt *) r->subquery; List *parsetrees; Query *query; + RangeTblEntry *rte; + RangeTblRef *rtr; + + /* + * We require user to supply an alias for a subselect, per SQL92. + * To relax this, we'd have to be prepared to gin up a unique alias + * for an unlabeled subselect. + */ + if (r->name == NULL) + elog(ERROR, "sub-select in FROM must have an alias"); /* * subquery node might not be SelectStmt if user wrote something like @@ -347,7 +374,7 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) * Analyze and transform the subquery as if it were an independent * statement (we do NOT want it to see the outer query as a parent). */ - parsetrees = parse_analyze(lcons(subquery, NIL), NULL); + parsetrees = parse_analyze(makeList1(subquery), NULL); /* * Check that we got something reasonable. Some of these conditions @@ -362,13 +389,24 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) if (query->commandType != CMD_SELECT) elog(ERROR, "Expected SELECT query from subselect in FROM"); - if (query->resultRelation != 0 || query->into != NULL) + if (query->resultRelation != 0 || query->into != NULL || query->isPortal) elog(ERROR, "Subselect in FROM may not have SELECT INTO"); + /* + * OK, build an RTE for the subquery. + */ + rte = addRangeTableEntryForSubquery(pstate, query, r->name, true); - elog(ERROR, "Subselect in FROM not done yet"); + /* + * We create a RangeTblRef, but we do not add it to the joinlist here. + * makeRangeTable will do so, if we are at top level of the FROM clause. + */ + rtr = makeNode(RangeTblRef); + /* assume new rte is at end */ + rtr->rtindex = length(pstate->p_rtable); + Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable)); - return NULL; + return rtr; } @@ -376,12 +414,12 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) * transformFromClauseItem - * Transform a FROM-clause item, adding any required entries to the * range table list being built in the ParseState, and return the - * transformed item ready to include in the jointree list. + * transformed item ready to include in the joinlist. * This routine can recurse to handle SQL92 JOIN expressions. * - * Aside from the primary return value (the transformed jointree item) + * Aside from the primary return value (the transformed joinlist item) * this routine also returns an integer list of the rangetable indexes - * of all the base relations represented in the jointree item. This + * of all the base relations represented in the joinlist item. This * list is needed for checking JOIN/ON conditions in higher levels. */ static Node * @@ -393,7 +431,7 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels) RangeTblRef *rtr; rtr = transformTableEntry(pstate, (RangeVar *) n); - *containedRels = lconsi(rtr->rtindex, NIL); + *containedRels = makeListi1(rtr->rtindex); return (Node *) rtr; } else if (IsA(n, RangeSubselect)) @@ -402,7 +440,7 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels) RangeTblRef *rtr; rtr = transformRangeSubselect(pstate, (RangeSubselect *) n); - *containedRels = lconsi(rtr->rtindex, NIL); + *containedRels = makeListi1(rtr->rtindex); return (Node *) rtr; } else if (IsA(n, JoinExpr)) @@ -599,7 +637,7 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels) a->lexpr = l_colvar; w->expr = (Node *) a; w->result = l_colvar; - c->args = lcons(w, NIL); + c->args = makeList1(w); c->defresult = r_colvar; colvar = transformExpr(pstate, (Node *) c, EXPR_COLUMN_FIRST); @@ -641,17 +679,17 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels) * The given table alias must be unique in the current nesting level, * ie it cannot match any RTE refname or jointable alias. This is * a bit painful to check because my own child joins are not yet in - * the pstate's jointree, so they have to be scanned separately. + * the pstate's joinlist, so they have to be scanned separately. */ if (j->alias) { - /* Check against previously created RTEs and jointree entries */ + /* Check against previously created RTEs and joinlist entries */ if (refnameRangeOrJoinEntry(pstate, j->alias->relname, NULL)) elog(ERROR, "Table name \"%s\" specified more than once", j->alias->relname); /* Check children */ - if (scanJoinTreeForRefname(j->larg, j->alias->relname) || - scanJoinTreeForRefname(j->rarg, j->alias->relname)) + if (scanJoinListForRefname(j->larg, j->alias->relname) || + scanJoinListForRefname(j->rarg, j->alias->relname)) elog(ERROR, "Table name \"%s\" specified more than once", j->alias->relname); /* |