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-rw-r--r--src/backend/parser/analyze.c19
-rw-r--r--src/backend/parser/parse_clause.c222
-rw-r--r--src/backend/parser/parse_relation.c38
3 files changed, 174 insertions, 105 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c0fe929e497..a3acf294534 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.232 2002/04/24 02:22:54 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.233 2002/04/28 19:54:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2075,7 +2075,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
Node *node;
List *lefttl,
*dtlist,
- *colMods,
+ *targetvars,
*targetnames,
*sv_namespace,
*sv_rtable;
@@ -2145,14 +2145,12 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
/*
* Generate dummy targetlist for outer query using column names of
* leftmost select and common datatypes of topmost set operation. Also
- * make a list of the column names for use in parsing ORDER BY.
- *
- * XXX colMods is a hack to provide a dummy typmod list below. We
- * should probably keep track of common typmod instead.
+ * make lists of the dummy vars and their names for use in parsing
+ * ORDER BY.
*/
qry->targetList = NIL;
+ targetvars = NIL;
targetnames = NIL;
- colMods = NIL;
lefttl = leftmostQuery->targetList;
foreach(dtlist, sostmt->colTypes)
{
@@ -2174,8 +2172,8 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
0);
qry->targetList = lappend(qry->targetList,
makeTargetEntry(resdom, expr));
+ targetvars = lappend(targetvars, expr);
targetnames = lappend(targetnames, makeString(colName));
- colMods = lappendi(colMods, -1);
lefttl = lnext(lefttl);
}
@@ -2232,10 +2230,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
jrte = addRangeTableEntryForJoin(NULL,
targetnames,
JOIN_INNER,
- sostmt->colTypes,
- colMods,
- NIL,
- NIL,
+ targetvars,
NULL,
true);
jrtr = makeNode(RangeTblRef);
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index 452f66284d8..6df4a4fd7dc 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 1.89 2002/04/16 23:08:11 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.90 2002/04/28 19:54:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -39,7 +39,7 @@
static char *clauseText[] = {"ORDER BY", "GROUP BY", "DISTINCT ON"};
-static void extractUniqueColumns(List *common_colnames,
+static void extractRemainingColumns(List *common_colnames,
List *src_colnames, List *src_colvars,
List **res_colnames, List **res_colvars);
static Node *transformJoinUsingClause(ParseState *pstate,
@@ -51,6 +51,8 @@ static RangeTblRef *transformRangeSubselect(ParseState *pstate,
RangeSubselect *r);
static Node *transformFromClauseItem(ParseState *pstate, Node *n,
List **containedRels);
+static Node *buildMergedJoinVar(JoinType jointype,
+ Var *l_colvar, Var *r_colvar);
static TargetEntry *findTargetlistEntry(ParseState *pstate, Node *node,
List *tlist, int clause);
static List *addTargetToSortList(TargetEntry *tle, List *sortlist,
@@ -194,9 +196,9 @@ interpretInhOption(InhOption inhOpt)
* Extract all not-in-common columns from column lists of a source table
*/
static void
-extractUniqueColumns(List *common_colnames,
- List *src_colnames, List *src_colvars,
- List **res_colnames, List **res_colvars)
+extractRemainingColumns(List *common_colnames,
+ List *src_colnames, List *src_colvars,
+ List **res_colnames, List **res_colvars)
{
List *new_colnames = NIL;
List *new_colvars = NIL;
@@ -496,10 +498,7 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
*res_colnames,
*l_colvars,
*r_colvars,
- *coltypes,
- *coltypmods,
- *leftcolnos,
- *rightcolnos;
+ *res_colvars;
Index leftrti,
rightrti;
RangeTblEntry *rte;
@@ -597,17 +596,14 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
* Now transform the join qualifications, if any.
*/
res_colnames = NIL;
- coltypes = NIL;
- coltypmods = NIL;
- leftcolnos = NIL;
- rightcolnos = NIL;
+ res_colvars = NIL;
if (j->using)
{
/*
* JOIN/USING (or NATURAL JOIN, as transformed above).
* Transform the list into an explicit ON-condition, and
- * generate a list of result columns.
+ * generate a list of merged result columns.
*/
List *ucols = j->using;
List *l_usingvars = NIL;
@@ -620,14 +616,22 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
{
char *u_colname = strVal(lfirst(ucol));
List *col;
- Var *l_colvar,
- *r_colvar;
- Oid outcoltype;
- int32 outcoltypmod;
int ndx;
int l_index = -1;
int r_index = -1;
+ Var *l_colvar,
+ *r_colvar;
+
+ /* Check for USING(foo,foo) */
+ foreach(col, res_colnames)
+ {
+ char *res_colname = strVal(lfirst(col));
+ if (strcmp(res_colname, u_colname) == 0)
+ elog(ERROR, "USING column name \"%s\" appears more than once", u_colname);
+ }
+
+ /* Find it in left input */
ndx = 0;
foreach(col, l_colnames)
{
@@ -645,6 +649,7 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
elog(ERROR, "JOIN/USING column \"%s\" not found in left table",
u_colname);
+ /* Find it in right input */
ndx = 0;
foreach(col, r_colnames)
{
@@ -667,30 +672,11 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
r_colvar = nth(r_index, r_colvars);
r_usingvars = lappend(r_usingvars, r_colvar);
- res_colnames = lappend(res_colnames,
- nth(l_index, l_colnames));
- /*
- * Choose output type if input types are dissimilar.
- */
- outcoltype = l_colvar->vartype;
- outcoltypmod = l_colvar->vartypmod;
- if (outcoltype != r_colvar->vartype)
- {
- outcoltype =
- select_common_type(makeListi2(l_colvar->vartype,
- r_colvar->vartype),
- "JOIN/USING");
- outcoltypmod = -1; /* ie, unknown */
- }
- else if (outcoltypmod != r_colvar->vartypmod)
- {
- /* same type, but not same typmod */
- outcoltypmod = -1; /* ie, unknown */
- }
- coltypes = lappendi(coltypes, outcoltype);
- coltypmods = lappendi(coltypmods, outcoltypmod);
- leftcolnos = lappendi(leftcolnos, l_index+1);
- rightcolnos = lappendi(rightcolnos, r_index+1);
+ res_colnames = lappend(res_colnames, lfirst(ucol));
+ res_colvars = lappend(res_colvars,
+ buildMergedJoinVar(j->jointype,
+ l_colvar,
+ r_colvar));
}
j->quals = transformJoinUsingClause(pstate,
@@ -708,34 +694,16 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
}
/* Add remaining columns from each side to the output columns */
- extractUniqueColumns(res_colnames,
- l_colnames, l_colvars,
- &l_colnames, &l_colvars);
- extractUniqueColumns(res_colnames,
- r_colnames, r_colvars,
- &r_colnames, &r_colvars);
+ extractRemainingColumns(res_colnames,
+ l_colnames, l_colvars,
+ &l_colnames, &l_colvars);
+ extractRemainingColumns(res_colnames,
+ r_colnames, r_colvars,
+ &r_colnames, &r_colvars);
res_colnames = nconc(res_colnames, l_colnames);
- while (l_colvars)
- {
- Var *l_var = (Var *) lfirst(l_colvars);
-
- coltypes = lappendi(coltypes, l_var->vartype);
- coltypmods = lappendi(coltypmods, l_var->vartypmod);
- leftcolnos = lappendi(leftcolnos, l_var->varattno);
- rightcolnos = lappendi(rightcolnos, 0);
- l_colvars = lnext(l_colvars);
- }
+ res_colvars = nconc(res_colvars, l_colvars);
res_colnames = nconc(res_colnames, r_colnames);
- while (r_colvars)
- {
- Var *r_var = (Var *) lfirst(r_colvars);
-
- coltypes = lappendi(coltypes, r_var->vartype);
- coltypmods = lappendi(coltypmods, r_var->vartypmod);
- leftcolnos = lappendi(leftcolnos, 0);
- rightcolnos = lappendi(rightcolnos, r_var->varattno);
- r_colvars = lnext(r_colvars);
- }
+ res_colvars = nconc(res_colvars, r_colvars);
/*
* Check alias (AS clause), if any.
@@ -753,11 +721,12 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
/*
* Now build an RTE for the result of the join
*/
- rte = addRangeTableEntryForJoin(pstate, res_colnames,
+ rte = addRangeTableEntryForJoin(pstate,
+ res_colnames,
j->jointype,
- coltypes, coltypmods,
- leftcolnos, rightcolnos,
- j->alias, true);
+ res_colvars,
+ j->alias,
+ true);
/* assume new rte is at end */
j->rtindex = length(pstate->p_rtable);
@@ -777,6 +746,115 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
* quiet */
}
+/*
+ * buildMergedJoinVar -
+ * generate a suitable replacement expression for a merged join column
+ */
+static Node *
+buildMergedJoinVar(JoinType jointype, Var *l_colvar, Var *r_colvar)
+{
+ Oid outcoltype;
+ int32 outcoltypmod;
+ Node *l_node,
+ *r_node,
+ *res_node;
+
+ /*
+ * Choose output type if input types are dissimilar.
+ */
+ outcoltype = l_colvar->vartype;
+ outcoltypmod = l_colvar->vartypmod;
+ if (outcoltype != r_colvar->vartype)
+ {
+ outcoltype = select_common_type(makeListi2(l_colvar->vartype,
+ r_colvar->vartype),
+ "JOIN/USING");
+ outcoltypmod = -1; /* ie, unknown */
+ }
+ else if (outcoltypmod != r_colvar->vartypmod)
+ {
+ /* same type, but not same typmod */
+ outcoltypmod = -1; /* ie, unknown */
+ }
+
+ /*
+ * Insert coercion functions if needed. Note that a difference in
+ * typmod can only happen if input has typmod but outcoltypmod is -1.
+ * In that case we insert a RelabelType to clearly mark that result's
+ * typmod is not same as input.
+ */
+ if (l_colvar->vartype != outcoltype)
+ l_node = coerce_type(NULL, (Node *) l_colvar, l_colvar->vartype,
+ outcoltype, outcoltypmod, false);
+ else if (l_colvar->vartypmod != outcoltypmod)
+ l_node = (Node *) makeRelabelType((Node *) l_colvar,
+ outcoltype, outcoltypmod);
+ else
+ l_node = (Node *) l_colvar;
+
+ if (r_colvar->vartype != outcoltype)
+ r_node = coerce_type(NULL, (Node *) r_colvar, r_colvar->vartype,
+ outcoltype, outcoltypmod, false);
+ else if (r_colvar->vartypmod != outcoltypmod)
+ r_node = (Node *) makeRelabelType((Node *) r_colvar,
+ outcoltype, outcoltypmod);
+ else
+ r_node = (Node *) r_colvar;
+
+ /*
+ * Choose what to emit
+ */
+ switch (jointype)
+ {
+ case JOIN_INNER:
+ /*
+ * We can use either var; prefer non-coerced one if available.
+ */
+ if (IsA(l_node, Var))
+ res_node = l_node;
+ else if (IsA(r_node, Var))
+ res_node = r_node;
+ else
+ res_node = l_node;
+ break;
+ case JOIN_LEFT:
+ /* Always use left var */
+ res_node = l_node;
+ break;
+ case JOIN_RIGHT:
+ /* Always use right var */
+ res_node = r_node;
+ break;
+ case JOIN_FULL:
+ {
+ /*
+ * Here we must build a COALESCE expression to ensure that
+ * the join output is non-null if either input is.
+ */
+ CaseExpr *c = makeNode(CaseExpr);
+ CaseWhen *w = makeNode(CaseWhen);
+ NullTest *n = makeNode(NullTest);
+
+ n->arg = l_node;
+ n->nulltesttype = IS_NOT_NULL;
+ w->expr = (Node *) n;
+ w->result = l_node;
+ c->casetype = outcoltype;
+ c->args = makeList1(w);
+ c->defresult = r_node;
+ res_node = (Node *) c;
+ break;
+ }
+ default:
+ elog(ERROR, "buildMergedJoinVar: unexpected jointype %d",
+ (int) jointype);
+ res_node = NULL; /* keep compiler quiet */
+ break;
+ }
+
+ return res_node;
+}
+
/*
* transformWhereClause -
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 9b386cb6366..b822a2378ba 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.67 2002/04/02 08:51:51 inoue Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.68 2002/04/28 19:54:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -681,10 +681,7 @@ RangeTblEntry *
addRangeTableEntryForJoin(ParseState *pstate,
List *colnames,
JoinType jointype,
- List *coltypes,
- List *coltypmods,
- List *leftcols,
- List *rightcols,
+ List *aliasvars,
Alias *alias,
bool inFromCl)
{
@@ -696,10 +693,7 @@ addRangeTableEntryForJoin(ParseState *pstate,
rte->relid = InvalidOid;
rte->subquery = NULL;
rte->jointype = jointype;
- rte->joincoltypes = coltypes;
- rte->joincoltypmods = coltypmods;
- rte->joinleftcols = leftcols;
- rte->joinrightcols = rightcols;
+ rte->joinaliasvars = aliasvars;
rte->alias = alias;
eref = alias ? (Alias *) copyObject(alias) : makeAlias("unnamed_join", NIL);
@@ -922,13 +916,12 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
{
/* Join RTE */
List *aliasp = rte->eref->colnames;
- List *coltypes = rte->joincoltypes;
- List *coltypmods = rte->joincoltypmods;
+ List *aliasvars = rte->joinaliasvars;
varattno = 0;
while (aliasp)
{
- Assert(coltypes && coltypmods);
+ Assert(aliasvars);
varattno++;
if (colnames)
@@ -940,21 +933,21 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
if (colvars)
{
+ Node *aliasvar = (Node *) lfirst(aliasvars);
Var *varnode;
varnode = makeVar(rtindex, varattno,
- (Oid) lfirsti(coltypes),
- (int32) lfirsti(coltypmods),
+ exprType(aliasvar),
+ exprTypmod(aliasvar),
sublevels_up);
*colvars = lappend(*colvars, varnode);
}
aliasp = lnext(aliasp);
- coltypes = lnext(coltypes);
- coltypmods = lnext(coltypmods);
+ aliasvars = lnext(aliasvars);
}
- Assert(coltypes == NIL && coltypmods == NIL);
+ Assert(aliasvars == NIL);
}
else
elog(ERROR, "expandRTE: unsupported RTE kind %d",
@@ -1091,10 +1084,13 @@ get_rte_attribute_type(RangeTblEntry *rte, AttrNumber attnum,
}
else if (rte->rtekind == RTE_JOIN)
{
- /* Join RTE --- get type info directly from join RTE */
- Assert(attnum > 0 && attnum <= length(rte->joincoltypes));
- *vartype = (Oid) nthi(attnum-1, rte->joincoltypes);
- *vartypmod = nthi(attnum-1, rte->joincoltypmods);
+ /* Join RTE --- get type info from join RTE's alias variable */
+ Node *aliasvar;
+
+ Assert(attnum > 0 && attnum <= length(rte->joinaliasvars));
+ aliasvar = (Node *) nth(attnum-1, rte->joinaliasvars);
+ *vartype = exprType(aliasvar);
+ *vartypmod = exprTypmod(aliasvar);
}
else
elog(ERROR, "get_rte_attribute_type: unsupported RTE kind %d",
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-07 17:46:17 +0000