int varno, Query *parsetree, bool *hasUpdate);
static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
+static List *get_generated_columns(Relation rel, int rt_index);
/*
if ((event == CMD_INSERT || event == CMD_UPDATE) &&
sub_action->commandType != CMD_UTILITY)
{
+ RangeTblEntry *new_rte = rt_fetch(new_varno, sub_action->rtable);
+ Relation new_rel;
+ List *gen_cols;
+
+ /*
+ * The target list does not contain entries for generated columns
+ * (they are removed by rewriteTargetListIU), so we must build entries
+ * for them here, so that new.gen_col can be rewritten correctly.
+ */
+ new_rel = relation_open(new_rte->relid, NoLock);
+ gen_cols = get_generated_columns(new_rel, new_varno);
+ relation_close(new_rel, NoLock);
+
+ /*
+ * The generated column expressions refer to new.attribute, so they
+ * must be rewritten before they can be used as replacements.
+ */
+ gen_cols = (List *)
+ ReplaceVarsFromTargetList((Node *) gen_cols,
+ new_varno,
+ 0,
+ new_rte,
+ parsetree->targetList,
+ (event == CMD_UPDATE) ?
+ REPLACEVARS_CHANGE_VARNO :
+ REPLACEVARS_SUBSTITUTE_NULL,
+ current_varno,
+ &sub_action->hasSubLinks);
+
+ /*
+ * Now rewrite new.attribute in sub_action, using both the target list
+ * and the rewritten generated column expressions.
+ */
sub_action = (Query *)
ReplaceVarsFromTargetList((Node *) sub_action,
new_varno,
0,
- rt_fetch(new_varno, sub_action->rtable),
- parsetree->targetList,
+ new_rte,
+ list_concat(gen_cols, parsetree->targetList),
(event == CMD_UPDATE) ?
REPLACEVARS_CHANGE_VARNO :
REPLACEVARS_SUBSTITUTE_NULL,
ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
/* Fix references to NEW */
if (event == CMD_INSERT || event == CMD_UPDATE)
+ {
+ RangeTblEntry *rte = rt_fetch(rt_index, parsetree->rtable);
+ Relation rel;
+ List *gen_cols;
+
+ /*
+ * As in rewriteRuleAction, build entries for generated columns so
+ * that new.gen_col in the rule qualification can be rewritten
+ * correctly.
+ */
+ rel = relation_open(rte->relid, NoLock);
+ gen_cols = get_generated_columns(rel, PRS2_NEW_VARNO);
+ relation_close(rel, NoLock);
+
+ /*
+ * The generated column expressions refer to new.attribute, so they
+ * must be rewritten before they can be used as replacements.
+ */
+ gen_cols = (List *)
+ ReplaceVarsFromTargetList((Node *) gen_cols,
+ PRS2_NEW_VARNO,
+ 0,
+ rte,
+ parsetree->targetList,
+ (event == CMD_UPDATE) ?
+ REPLACEVARS_CHANGE_VARNO :
+ REPLACEVARS_SUBSTITUTE_NULL,
+ rt_index,
+ &parsetree->hasSubLinks);
+
new_qual = ReplaceVarsFromTargetList(new_qual,
PRS2_NEW_VARNO,
0,
- rt_fetch(rt_index,
- parsetree->rtable),
- parsetree->targetList,
+ rte,
+ list_concat(gen_cols,
+ parsetree->targetList),
(event == CMD_UPDATE) ?
REPLACEVARS_CHANGE_VARNO :
REPLACEVARS_SUBSTITUTE_NULL,
rt_index,
&parsetree->hasSubLinks);
+ }
/* And attach the fixed qual */
AddInvertedQual(parsetree, new_qual);
}
+/*
+ * Get a table's generated columns
+ *
+ * Returns a list of TargetEntry, one for each generated column, containing
+ * the attribute numbers and generation expressions.
+ */
+static List *
+get_generated_columns(Relation rel, int rt_index)
+{
+ List *gen_cols = NIL;
+ TupleDesc tupdesc;
+
+ tupdesc = RelationGetDescr(rel);
+ if (tupdesc->constr && tupdesc->constr->has_generated_stored)
+ {
+ for (int i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
+
+ if (attr->attgenerated == ATTRIBUTE_GENERATED_STORED)
+ {
+ Node *defexpr;
+ TargetEntry *te;
+ Oid attcollid;
+
+ defexpr = build_column_default(rel, i + 1);
+ if (defexpr == NULL)
+ elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
+ i + 1, RelationGetRelationName(rel));
+
+ /*
+ * If the column definition has a collation and it is
+ * different from the collation of the generation expression,
+ * put a COLLATE clause around the expression.
+ */
+ attcollid = attr->attcollation;
+ if (attcollid && attcollid != exprCollation(defexpr))
+ {
+ CollateExpr *ce = makeNode(CollateExpr);
+
+ ce->arg = (Expr *) defexpr;
+ ce->collOid = attcollid;
+ ce->location = -1;
+
+ defexpr = (Node *) ce;
+ }
+
+ ChangeVarNodes(defexpr, 1, rt_index, 0);
+
+ te = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
+ gen_cols = lappend(gen_cols, te);
+ }
+ }
+ }
+
+ return gen_cols;
+}
+
+
/*
* QueryRewrite -
* Primary entry point to the query rewriter.
c | integer | | |
x | integer | | | generated always as (b * 2) stored
+-- rule actions referring to generated columns:
+-- NEW.b in a rule action should reflect the generated column's new value
+CREATE TABLE gtest_rule (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_rule_log (op text, old_b int, new_b int);
+CREATE RULE gtest_rule_upd AS ON UPDATE TO gtest_rule
+ DO ALSO INSERT INTO gtest_rule_log VALUES ('UPD', OLD.b, NEW.b);
+CREATE RULE gtest_rule_ins AS ON INSERT TO gtest_rule
+ DO ALSO INSERT INTO gtest_rule_log VALUES ('INS', NULL, NEW.b);
+INSERT INTO gtest_rule (a) VALUES (1);
+UPDATE gtest_rule SET a = 10;
+UPDATE gtest_rule SET a = (SELECT max(b) FROM gtest_rule);
+SELECT * FROM gtest_rule_log;
+ op | old_b | new_b
+-----+-------+-------
+ INS | | 2
+ UPD | 2 | 20
+ UPD | 20 | 40
+(3 rows)
+
+DROP RULE gtest_rule_upd ON gtest_rule;
+DROP RULE gtest_rule_ins ON gtest_rule;
+DROP TABLE gtest_rule_log;
+-- rule quals referring to generated columns:
+-- NEW.b in the rule qual should reflect the generated column's new value
+CREATE RULE gtest_rule_qual AS ON UPDATE TO gtest_rule WHERE NEW.b > 100
+ DO INSTEAD NOTHING;
+UPDATE gtest_rule SET a = 100;
+SELECT * FROM gtest_rule;
+ a | b
+----+----
+ 20 | 40
+(1 row)
+
+DROP TABLE gtest_rule;
CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
\d gtest28*
+
+-- rule actions referring to generated columns:
+-- NEW.b in a rule action should reflect the generated column's new value
+CREATE TABLE gtest_rule (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_rule_log (op text, old_b int, new_b int);
+CREATE RULE gtest_rule_upd AS ON UPDATE TO gtest_rule
+ DO ALSO INSERT INTO gtest_rule_log VALUES ('UPD', OLD.b, NEW.b);
+CREATE RULE gtest_rule_ins AS ON INSERT TO gtest_rule
+ DO ALSO INSERT INTO gtest_rule_log VALUES ('INS', NULL, NEW.b);
+INSERT INTO gtest_rule (a) VALUES (1);
+UPDATE gtest_rule SET a = 10;
+UPDATE gtest_rule SET a = (SELECT max(b) FROM gtest_rule);
+SELECT * FROM gtest_rule_log;
+DROP RULE gtest_rule_upd ON gtest_rule;
+DROP RULE gtest_rule_ins ON gtest_rule;
+DROP TABLE gtest_rule_log;
+
+-- rule quals referring to generated columns:
+-- NEW.b in the rule qual should reflect the generated column's new value
+CREATE RULE gtest_rule_qual AS ON UPDATE TO gtest_rule WHERE NEW.b > 100
+ DO INSTEAD NOTHING;
+UPDATE gtest_rule SET a = 100;
+SELECT * FROM gtest_rule;
+DROP TABLE gtest_rule;
projects / thirdparty / postgresql.git / commitdiff
