/* Just copy the entry and fall through to adjust phlevelsup etc */
newnode = copyObject(rcon->rv_cache[varattno]);
}
- else if (varattno == InvalidAttrNumber)
+ else
{
- /* Must expand whole-tuple reference into RowExpr */
- RowExpr *rowexpr;
- List *colnames;
- List *fields;
- bool save_wrap_non_vars = rcon->wrap_non_vars;
- int save_sublevelsup = context->sublevels_up;
-
/*
- * If generating an expansion for a var of a named rowtype (ie, this
- * is a plain relation RTE), then we must include dummy items for
- * dropped columns. If the var is RECORD (ie, this is a JOIN), then
- * omit dropped columns. In the latter case, attach column names to
- * the RowExpr for use of the executor and ruleutils.c.
- *
- * In order to be able to cache the results, we always generate the
- * expansion with varlevelsup = 0, and then adjust below if needed.
+ * Generate the replacement expression. This takes care of expanding
+ * wholerow references and dealing with non-default varreturningtype.
*/
- expandRTE(rcon->target_rte,
- var->varno, 0 /* not varlevelsup */ ,
- var->varreturningtype, var->location,
- (var->vartype != RECORDOID),
- &colnames, &fields);
- /* Expand the generated per-field Vars, but don't insert PHVs there */
- rcon->wrap_non_vars = false;
- context->sublevels_up = 0; /* to match the expandRTE output */
- fields = (List *) replace_rte_variables_mutator((Node *) fields,
- context);
- rcon->wrap_non_vars = save_wrap_non_vars;
- context->sublevels_up = save_sublevelsup;
-
- rowexpr = makeNode(RowExpr);
- rowexpr->args = fields;
- rowexpr->row_typeid = var->vartype;
- rowexpr->row_format = COERCE_IMPLICIT_CAST;
- rowexpr->colnames = (var->vartype == RECORDOID) ? colnames : NIL;
- rowexpr->location = var->location;
- newnode = (Node *) rowexpr;
-
- /* Handle any OLD/NEW RETURNING list Vars */
- if (var->varreturningtype != VAR_RETURNING_DEFAULT)
- {
- /*
- * Wrap the RowExpr in a ReturningExpr node, so that the executor
- * returns NULL if the OLD/NEW row does not exist.
- */
- ReturningExpr *rexpr = makeNode(ReturningExpr);
-
- rexpr->retlevelsup = 0;
- rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
- rexpr->retexpr = (Expr *) newnode;
-
- newnode = (Node *) rexpr;
- }
-
- /*
- * Insert PlaceHolderVar if needed. Notice that we are wrapping one
- * PlaceHolderVar around the whole RowExpr, rather than putting one
- * around each element of the row. This is because we need the
- * expression to yield NULL, not ROW(NULL,NULL,...) when it is forced
- * to null by an outer join.
- */
- if (need_phv)
- {
- newnode = (Node *)
- make_placeholder_expr(rcon->root,
- (Expr *) newnode,
- bms_make_singleton(rcon->varno));
- /* cache it with the PHV, and with phlevelsup etc not set yet */
- rcon->rv_cache[InvalidAttrNumber] = copyObject(newnode);
- }
- }
- else
- {
- /* Normal case referencing one targetlist element */
- TargetEntry *tle = get_tle_by_resno(rcon->targetlist, varattno);
-
- if (tle == NULL) /* shouldn't happen */
- elog(ERROR, "could not find attribute %d in subquery targetlist",
- varattno);
-
- /* Make a copy of the tlist item to return */
- newnode = (Node *) copyObject(tle->expr);
-
- /* Handle any OLD/NEW RETURNING list Vars */
- if (var->varreturningtype != VAR_RETURNING_DEFAULT)
- {
- /*
- * Copy varreturningtype onto any Vars in the tlist item that
- * refer to result_relation (which had better be non-zero).
- */
- if (rcon->result_relation == 0)
- elog(ERROR, "variable returning old/new found outside RETURNING list");
-
- SetVarReturningType((Node *) newnode, rcon->result_relation,
- 0, var->varreturningtype);
-
- /*
- * If the replacement expression in the targetlist is not simply a
- * Var referencing result_relation, wrap it in a ReturningExpr
- * node, so that the executor returns NULL if the OLD/NEW row does
- * not exist.
- */
- if (!IsA(newnode, Var) ||
- ((Var *) newnode)->varno != rcon->result_relation ||
- ((Var *) newnode)->varlevelsup != 0)
- {
- ReturningExpr *rexpr = makeNode(ReturningExpr);
-
- rexpr->retlevelsup = 0;
- rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
- rexpr->retexpr = (Expr *) newnode;
-
- newnode = (Node *) rexpr;
- }
- }
+ newnode = ReplaceVarFromTargetList(var,
+ rcon->target_rte,
+ rcon->targetlist,
+ rcon->result_relation,
+ REPLACEVARS_REPORT_ERROR,
+ 0);
/* Insert PlaceHolderVar if needed */
if (need_phv)
{
bool wrap;
- if (newnode && IsA(newnode, Var) &&
- ((Var *) newnode)->varlevelsup == 0)
+ if (varattno == InvalidAttrNumber)
+ {
+ /*
+ * Insert PlaceHolderVar for whole-tuple reference. Notice
+ * that we are wrapping one PlaceHolderVar around the whole
+ * RowExpr, rather than putting one around each element of the
+ * row. This is because we need the expression to yield NULL,
+ * not ROW(NULL,NULL,...) when it is forced to null by an
+ * outer join.
+ */
+ wrap = true;
+ }
+ else if (newnode && IsA(newnode, Var) &&
+ ((Var *) newnode)->varlevelsup == 0)
{
/*
* Simple Vars always escape being wrapped, unless they are
* Cache it if possible (ie, if the attno is in range, which
* it probably always should be).
*/
- if (varattno > InvalidAttrNumber &&
+ if (varattno >= InvalidAttrNumber &&
varattno <= list_length(rcon->targetlist))
rcon->rv_cache[varattno] = copyObject(newnode);
}
return expression_tree_walker(node, SetVarReturningType_walker, context);
}
-void
+static void
SetVarReturningType(Node *node, int result_relation, int sublevels_up,
VarReturningType returning_type)
{
* referencing result_relation, it is wrapped in a ReturningExpr node (causing
* the executor to return NULL if the OLD/NEW row doesn't exist).
*
+ * Note that ReplaceVarFromTargetList always generates the replacement
+ * expression with varlevelsup = 0. The caller is responsible for adjusting
+ * the varlevelsup if needed. This simplifies the caller's life if it wants to
+ * cache the replacement expressions.
+ *
* outer_hasSubLinks works the same as for replace_rte_variables().
*/
replace_rte_variables_context *context)
{
ReplaceVarsFromTargetList_context *rcon = (ReplaceVarsFromTargetList_context *) context->callback_arg;
+ Node *newnode;
+
+ newnode = ReplaceVarFromTargetList(var,
+ rcon->target_rte,
+ rcon->targetlist,
+ rcon->result_relation,
+ rcon->nomatch_option,
+ rcon->nomatch_varno);
+
+ /* Must adjust varlevelsup if replaced Var is within a subquery */
+ if (var->varlevelsup > 0)
+ IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
+
+ return newnode;
+}
+
+Node *
+ReplaceVarFromTargetList(Var *var,
+ RangeTblEntry *target_rte,
+ List *targetlist,
+ int result_relation,
+ ReplaceVarsNoMatchOption nomatch_option,
+ int nomatch_varno)
+{
TargetEntry *tle;
if (var->varattno == InvalidAttrNumber)
RowExpr *rowexpr;
List *colnames;
List *fields;
+ ListCell *lc;
/*
* If generating an expansion for a var of a named rowtype (ie, this
* omit dropped columns. In the latter case, attach column names to
* the RowExpr for use of the executor and ruleutils.c.
*
+ * In order to be able to cache the results, we always generate the
+ * expansion with varlevelsup = 0. The caller is responsible for
+ * adjusting it if needed.
+ *
* The varreturningtype is copied onto each individual field Var, so
* that it is handled correctly when we recurse.
*/
- expandRTE(rcon->target_rte,
- var->varno, var->varlevelsup, var->varreturningtype,
- var->location, (var->vartype != RECORDOID),
+ expandRTE(target_rte,
+ var->varno, 0 /* not varlevelsup */ ,
+ var->varreturningtype, var->location,
+ (var->vartype != RECORDOID),
&colnames, &fields);
- /* Adjust the generated per-field Vars... */
- fields = (List *) replace_rte_variables_mutator((Node *) fields,
- context);
rowexpr = makeNode(RowExpr);
- rowexpr->args = fields;
+ /* the fields will be set below */
+ rowexpr->args = NIL;
rowexpr->row_typeid = var->vartype;
rowexpr->row_format = COERCE_IMPLICIT_CAST;
rowexpr->colnames = (var->vartype == RECORDOID) ? colnames : NIL;
rowexpr->location = var->location;
+ /* Adjust the generated per-field Vars... */
+ foreach(lc, fields)
+ {
+ Node *field = lfirst(lc);
+
+ if (field && IsA(field, Var))
+ field = ReplaceVarFromTargetList((Var *) field,
+ target_rte,
+ targetlist,
+ result_relation,
+ nomatch_option,
+ nomatch_varno);
+ rowexpr->args = lappend(rowexpr->args, field);
+ }
/* Wrap it in a ReturningExpr, if needed, per comments above */
if (var->varreturningtype != VAR_RETURNING_DEFAULT)
{
ReturningExpr *rexpr = makeNode(ReturningExpr);
- rexpr->retlevelsup = var->varlevelsup;
+ rexpr->retlevelsup = 0;
rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
rexpr->retexpr = (Expr *) rowexpr;
}
/* Normal case referencing one targetlist element */
- tle = get_tle_by_resno(rcon->targetlist, var->varattno);
+ tle = get_tle_by_resno(targetlist, var->varattno);
if (tle == NULL || tle->resjunk)
{
/* Failed to find column in targetlist */
- switch (rcon->nomatch_option)
+ switch (nomatch_option)
{
case REPLACEVARS_REPORT_ERROR:
/* fall through, throw error below */
case REPLACEVARS_CHANGE_VARNO:
var = copyObject(var);
- var->varno = rcon->nomatch_varno;
+ var->varno = nomatch_varno;
+ var->varlevelsup = 0;
/* we leave the syntactic referent alone */
return (Node *) var;
/* Make a copy of the tlist item to return */
Expr *newnode = copyObject(tle->expr);
- /* Must adjust varlevelsup if tlist item is from higher query */
- if (var->varlevelsup > 0)
- IncrementVarSublevelsUp((Node *) newnode, var->varlevelsup, 0);
-
/*
* Check to see if the tlist item contains a PARAM_MULTIEXPR Param,
* and throw error if so. This case could only happen when expanding
* Copy varreturningtype onto any Vars in the tlist item that
* refer to result_relation (which had better be non-zero).
*/
- if (rcon->result_relation == 0)
+ if (result_relation == 0)
elog(ERROR, "variable returning old/new found outside RETURNING list");
- SetVarReturningType((Node *) newnode, rcon->result_relation,
- var->varlevelsup, var->varreturningtype);
+ SetVarReturningType((Node *) newnode, result_relation,
+ 0, var->varreturningtype);
/* Wrap it in a ReturningExpr, if needed, per comments above */
if (!IsA(newnode, Var) ||
- ((Var *) newnode)->varno != rcon->result_relation ||
- ((Var *) newnode)->varlevelsup != var->varlevelsup)
+ ((Var *) newnode)->varno != result_relation ||
+ ((Var *) newnode)->varlevelsup != 0)
{
ReturningExpr *rexpr = makeNode(ReturningExpr);
- rexpr->retlevelsup = var->varlevelsup;
+ rexpr->retlevelsup = 0;
rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
rexpr->retexpr = newnode;
extern void IncrementVarSublevelsUp_rtable(List *rtable,
int delta_sublevels_up, int min_sublevels_up);
-extern void SetVarReturningType(Node *node, int result_relation, int sublevels_up,
- VarReturningType returning_type);
-
extern bool rangeTableEntry_used(Node *node, int rt_index,
int sublevels_up);
const struct AttrMap *attno_map,
Oid to_rowtype, bool *found_whole_row);
+extern Node *ReplaceVarFromTargetList(Var *var,
+ RangeTblEntry *target_rte,
+ List *targetlist,
+ int result_relation,
+ ReplaceVarsNoMatchOption nomatch_option,
+ int nomatch_varno);
extern Node *ReplaceVarsFromTargetList(Node *node,
int target_varno, int sublevels_up,
RangeTblEntry *target_rte,
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