"Jonathan S. Katz" <jk...@postgresql.org> writes:
> I spoke too soon -- I was looking at the wrong logs. I did reproduce it
> with UPDATE, but not INSERT.
It can be reproduced with INSERT too, on the same principle as the others:
put the DML command inside a WITH, and give it an alias conflicting with
the outer query.
Being a lazy sort, I tried to collapse all three cases into a single
test case, and observed something I hadn't thought of: we disambiguate
aliases in a WITH query with respect to the outer query, but not with
respect to other WITH queries. This makes the example (see attached)
a bit more confusing than I would have hoped. However, the same sort
of thing happens within other kinds of nested subqueries, so I think
it's probably all right as-is. In any case, changing this aspect
would require a significantly bigger patch with more risk of unwanted
side-effects.
To fix it, I pulled out the print-an-alias logic within
get_from_clause_item and called that new function for
INSERT/UPDATE/DELETE. This is a bit of overkill perhaps, because
only the RTE_RELATION case can be needed by these other callers, but
it seemed like a sane refactorization.
I've not tested, but I imagine this will need patched all the way back.
The rule case should be reachable in all supported versions.
regards, tom lane
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9ac42efdbc..6dc117dea8 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -475,6 +475,8 @@ static void get_from_clause(Query *query, const char *prefix,
deparse_context *context);
static void get_from_clause_item(Node *jtnode, Query *query,
deparse_context *context);
+static void get_rte_alias(RangeTblEntry *rte, int varno, bool use_as,
+ deparse_context *context);
static void get_column_alias_list(deparse_columns *colinfo,
deparse_context *context);
static void get_from_clause_coldeflist(RangeTblFunction *rtfunc,
@@ -6648,12 +6650,14 @@ get_insert_query_def(Query *query, deparse_context *context,
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
- appendStringInfo(buf, "INSERT INTO %s ",
+ appendStringInfo(buf, "INSERT INTO %s",
generate_relation_name(rte->relid, NIL));
- /* INSERT requires AS keyword for target alias */
- if (rte->alias != NULL)
- appendStringInfo(buf, "AS %s ",
- quote_identifier(rte->alias->aliasname));
+
+ /* Print the relation alias, if needed; INSERT requires explicit AS */
+ get_rte_alias(rte, query->resultRelation, true, context);
+
+ /* always want a space here */
+ appendStringInfoChar(buf, ' ');
/*
* Add the insert-column-names list. Any indirection decoration needed on
@@ -6835,9 +6839,10 @@ get_update_query_def(Query *query, deparse_context *context,
appendStringInfo(buf, "UPDATE %s%s",
only_marker(rte),
generate_relation_name(rte->relid, NIL));
- if (rte->alias != NULL)
- appendStringInfo(buf, " %s",
- quote_identifier(rte->alias->aliasname));
+
+ /* Print the relation alias, if needed */
+ get_rte_alias(rte, query->resultRelation, false, context);
+
appendStringInfoString(buf, " SET ");
/* Deparse targetlist */
@@ -7043,9 +7048,9 @@ get_delete_query_def(Query *query, deparse_context *context,
appendStringInfo(buf, "DELETE FROM %s%s",
only_marker(rte),
generate_relation_name(rte->relid, NIL));
- if (rte->alias != NULL)
- appendStringInfo(buf, " %s",
- quote_identifier(rte->alias->aliasname));
+
+ /* Print the relation alias, if needed */
+ get_rte_alias(rte, query->resultRelation, false, context);
/* Add the USING clause if given */
get_from_clause(query, " USING ", context);
@@ -10887,10 +10892,8 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
- char *refname = get_rtable_name(varno, context);
deparse_columns *colinfo = deparse_columns_fetch(varno, dpns);
RangeTblFunction *rtfunc1 = NULL;
- bool printalias;
if (rte->lateral)
appendStringInfoString(buf, "LATERAL ");
@@ -11027,59 +11030,7 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
}
/* Print the relation alias, if needed */
- printalias = false;
- if (rte->alias != NULL)
- {
- /* Always print alias if user provided one */
- printalias = true;
- }
- else if (colinfo->printaliases)
- {
- /* Always print alias if we need to print column aliases */
- printalias = true;
- }
- else if (rte->rtekind == RTE_RELATION)
- {
- /*
- * No need to print alias if it's same as relation name (this
- * would normally be the case, but not if set_rtable_names had to
- * resolve a conflict).
- */
- if (strcmp(refname, get_relation_name(rte->relid)) != 0)
- printalias = true;
- }
- else if (rte->rtekind == RTE_FUNCTION)
- {
- /*
- * For a function RTE, always print alias. This covers possible
- * renaming of the function and/or instability of the
- * FigureColname rules for things that aren't simple functions.
- * Note we'd need to force it anyway for the columndef list case.
- */
- printalias = true;
- }
- else if (rte->rtekind == RTE_SUBQUERY ||
- rte->rtekind == RTE_VALUES)
- {
- /*
- * For a subquery, always print alias. This makes the output SQL
- * spec-compliant, even though we allow the alias to be omitted on
- * input.
- */
- printalias = true;
- }
- else if (rte->rtekind == RTE_CTE)
- {
- /*
- * No need to print alias if it's same as CTE name (this would
- * normally be the case, but not if set_rtable_names had to
- * resolve a conflict).
- */
- if (strcmp(refname, rte->ctename) != 0)
- printalias = true;
- }
- if (printalias)
- appendStringInfo(buf, " %s", quote_identifier(refname));
+ get_rte_alias(rte, varno, false, context);
/* Print the column definitions or aliases, if needed */
if (rtfunc1 && rtfunc1->funccolnames != NIL)
@@ -11217,6 +11168,77 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
(int) nodeTag(jtnode));
}
+/*
+ * get_rte_alias - print the relation's alias, if needed
+ *
+ * If printed, the alias is preceded by a space, or by " AS " if use_as is true.
+ */
+static void
+get_rte_alias(RangeTblEntry *rte, int varno, bool use_as,
+ deparse_context *context)
+{
+ deparse_namespace *dpns = (deparse_namespace *) linitial(context->namespaces);
+ char *refname = get_rtable_name(varno, context);
+ deparse_columns *colinfo = deparse_columns_fetch(varno, dpns);
+ bool printalias = false;
+
+ if (rte->alias != NULL)
+ {
+ /* Always print alias if user provided one */
+ printalias = true;
+ }
+ else if (colinfo->printaliases)
+ {
+ /* Always print alias if we need to print column aliases */
+ printalias = true;
+ }
+ else if (rte->rtekind == RTE_RELATION)
+ {
+ /*
+ * No need to print alias if it's same as relation name (this would
+ * normally be the case, but not if set_rtable_names had to resolve a
+ * conflict).
+ */
+ if (strcmp(refname, get_relation_name(rte->relid)) != 0)
+ printalias = true;
+ }
+ else if (rte->rtekind == RTE_FUNCTION)
+ {
+ /*
+ * For a function RTE, always print alias. This covers possible
+ * renaming of the function and/or instability of the FigureColname
+ * rules for things that aren't simple functions. Note we'd need to
+ * force it anyway for the columndef list case.
+ */
+ printalias = true;
+ }
+ else if (rte->rtekind == RTE_SUBQUERY ||
+ rte->rtekind == RTE_VALUES)
+ {
+ /*
+ * For a subquery, always print alias. This makes the output
+ * SQL-spec-compliant, even though we allow such aliases to be omitted
+ * on input.
+ */
+ printalias = true;
+ }
+ else if (rte->rtekind == RTE_CTE)
+ {
+ /*
+ * No need to print alias if it's same as CTE name (this would
+ * normally be the case, but not if set_rtable_names had to resolve a
+ * conflict).
+ */
+ if (strcmp(refname, rte->ctename) != 0)
+ printalias = true;
+ }
+
+ if (printalias)
+ appendStringInfo(context->buf, "%s%s",
+ use_as ? " AS " : " ",
+ quote_identifier(refname));
+}
+
/*
* get_column_alias_list - print column alias list for an RTE
*
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 174b725fff..a3a5a62329 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2998,28 +2998,21 @@ select * from rules_log;
(16 rows)
create rule r4 as on delete to rules_src do notify rules_src_deletion;
-\d+ rules_src
- Table "public.rules_src"
- Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
---------+---------+-----------+----------+---------+---------+--------------+-------------
- f1 | integer | | | | plain | |
- f2 | integer | | | 0 | plain | |
-Rules:
- r1 AS
- ON UPDATE TO rules_src DO INSERT INTO rules_log (f1, f2, tag, id) VALUES (old.f1,old.f2,'old'::text,DEFAULT), (new.f1,new.f2,'new'::text,DEFAULT)
- r2 AS
- ON UPDATE TO rules_src DO VALUES (old.f1,old.f2,'old'::text), (new.f1,new.f2,'new'::text)
- r3 AS
- ON INSERT TO rules_src DO INSERT INTO rules_log (f1, f2, tag, id) VALUES (NULL::integer,NULL::integer,'-'::text,DEFAULT), (new.f1,new.f2,'new'::text,DEFAULT)
- r4 AS
- ON DELETE TO rules_src DO
- NOTIFY rules_src_deletion
-
--
-- Ensure an aliased target relation for insert is correctly deparsed.
--
create rule r5 as on insert to rules_src do instead insert into rules_log AS trgt SELECT NEW.* RETURNING trgt.f1, trgt.f2;
create rule r6 as on update to rules_src do instead UPDATE rules_log AS trgt SET tag = 'updated' WHERE trgt.f1 = new.f1;
+--
+-- Check deparse disambiguation of INSERT/UPDATE/DELETE targets.
+--
+create rule r7 as on delete to rules_src do instead
+ with wins as (insert into int4_tbl as trgt values (0) returning *),
+ wupd as (update int4_tbl trgt set f1 = f1+1 returning *),
+ wdel as (delete from int4_tbl trgt where f1 = 0 returning *)
+ insert into rules_log AS trgt select old.* from wins, wupd, wdel
+ returning trgt.f1, trgt.f2;
+-- check display of all rules added above
\d+ rules_src
Table "public.rules_src"
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
@@ -3044,6 +3037,26 @@ Rules:
r6 AS
ON UPDATE TO rules_src DO INSTEAD UPDATE rules_log trgt SET tag = 'updated'::text
WHERE trgt.f1 = new.f1
+ r7 AS
+ ON DELETE TO rules_src DO INSTEAD WITH wins AS (
+ INSERT INTO int4_tbl AS trgt_1 (f1)
+ VALUES (0)
+ RETURNING trgt_1.f1
+ ), wupd AS (
+ UPDATE int4_tbl trgt_1 SET f1 = trgt_1.f1 + 1
+ RETURNING trgt_1.f1
+ ), wdel AS (
+ DELETE FROM int4_tbl trgt_1
+ WHERE trgt_1.f1 = 0
+ RETURNING trgt_1.f1
+ )
+ INSERT INTO rules_log AS trgt (f1, f2) SELECT old.f1,
+ old.f2
+ FROM wins,
+ wupd,
+ wdel
+ RETURNING trgt.f1,
+ trgt.f2
--
-- Also check multiassignment deparsing.
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
index 1f858129b8..ac1a4ce554 100644
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -1015,13 +1015,24 @@ insert into rules_src values(22,23), (33,default);
select * from rules_src;
select * from rules_log;
create rule r4 as on delete to rules_src do notify rules_src_deletion;
-\d+ rules_src
--
-- Ensure an aliased target relation for insert is correctly deparsed.
--
create rule r5 as on insert to rules_src do instead insert into rules_log AS trgt SELECT NEW.* RETURNING trgt.f1, trgt.f2;
create rule r6 as on update to rules_src do instead UPDATE rules_log AS trgt SET tag = 'updated' WHERE trgt.f1 = new.f1;
+
+--
+-- Check deparse disambiguation of INSERT/UPDATE/DELETE targets.
+--
+create rule r7 as on delete to rules_src do instead
+ with wins as (insert into int4_tbl as trgt values (0) returning *),
+ wupd as (update int4_tbl trgt set f1 = f1+1 returning *),
+ wdel as (delete from int4_tbl trgt where f1 = 0 returning *)
+ insert into rules_log AS trgt select old.* from wins, wupd, wdel
+ returning trgt.f1, trgt.f2;
+
+-- check display of all rules added above
\d+ rules_src
--
