Fix dumping of views that are just VALUES(...) but have column aliases.

The "simple" path for printing VALUES clauses doesn't work if we need
to attach nondefault column aliases, because there's noplace to do that
in the minimal VALUES() syntax.  So modify get_simple_values_rte() to
detect nondefault aliases and treat that as a non-simple case.  This
further exposes that the "non-simple" path never actually worked;
it didn't produce valid syntax.  Fix that too.  Per bug #12789 from
Curtis McEnroe, and analysis by Andrew Gierth.

Back-patch to all supported branches.  Before 9.3, this also requires
back-patching the part of commit 092d7ded29
that created get_simple_values_rte() to begin with; inserting the extra
test into the old factorization of that logic would've been too messy.
This commit is contained in:
Tom Lane 2015-02-25 12:01:12 -05:00
parent 8794bf1ca1
commit e9f1c01b71
3 changed files with 107 additions and 4 deletions

View File

@ -4498,10 +4498,7 @@ get_simple_values_rte(Query *query)
/*
* We want to return TRUE even if the Query also contains OLD or NEW rule
* RTEs. So the idea is to scan the rtable and see if there is only one
* inFromCl RTE that is a VALUES RTE. We don't look at the targetlist at
* all. This is okay because parser/analyze.c will never generate a
* "bare" VALUES RTE --- they only appear inside auto-generated
* sub-queries with very restricted structure.
* inFromCl RTE that is a VALUES RTE.
*/
foreach(lc, query->rtable)
{
@ -4518,6 +4515,33 @@ get_simple_values_rte(Query *query)
else
return NULL; /* something else -> not simple VALUES */
}
/*
* We don't need to check the targetlist in any great detail, because
* parser/analyze.c will never generate a "bare" VALUES RTE --- they only
* appear inside auto-generated sub-queries with very restricted
* structure. However, DefineView might have modified the tlist by
* injecting new column aliases; so compare tlist resnames against the
* RTE's names to detect that.
*/
if (result)
{
ListCell *lcn;
if (list_length(query->targetList) != list_length(result->eref->colnames))
return NULL; /* this probably cannot happen */
forboth(lc, query->targetList, lcn, result->eref->colnames)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
char *cname = strVal(lfirst(lcn));
if (tle->resjunk)
return NULL; /* this probably cannot happen */
if (tle->resname == NULL || strcmp(tle->resname, cname) != 0)
return NULL; /* column name has been changed */
}
}
return result;
}
@ -8517,7 +8541,9 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
break;
case RTE_VALUES:
/* Values list RTE */
appendStringInfoChar(buf, '(');
get_values_def(rte->values_lists, context);
appendStringInfoChar(buf, ')');
break;
case RTE_CTE:
appendStringInfoString(buf, quote_identifier(rte->ctename));
@ -8559,6 +8585,11 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
*/
printalias = true;
}
else if (rte->rtekind == RTE_VALUES)
{
/* Alias is syntactically required for VALUES */
printalias = true;
}
else if (rte->rtekind == RTE_CTE)
{
/*

View File

@ -2507,6 +2507,7 @@ select * from only t1_2;
19
(10 rows)
reset constraint_exclusion;
-- test various flavors of pg_get_viewdef()
select pg_get_viewdef('shoe'::regclass) as unpretty;
unpretty
@ -2678,3 +2679,56 @@ ALTER RULE "_RETURN" ON rule_v1 RENAME TO abc; -- ON SELECT rule cannot be renam
ERROR: renaming an ON SELECT rule is not allowed
DROP VIEW rule_v1;
DROP TABLE rule_t1;
--
-- check display of VALUES in view definitions
--
create view rule_v1 as values(1,2);
\d+ rule_v1
View "public.rule_v1"
Column | Type | Modifiers | Storage | Description
---------+---------+-----------+---------+-------------
column1 | integer | | plain |
column2 | integer | | plain |
View definition:
VALUES (1,2);
drop view rule_v1;
create view rule_v1(x) as values(1,2);
\d+ rule_v1
View "public.rule_v1"
Column | Type | Modifiers | Storage | Description
---------+---------+-----------+---------+-------------
x | integer | | plain |
column2 | integer | | plain |
View definition:
SELECT "*VALUES*".column1 AS x,
"*VALUES*".column2
FROM (VALUES (1,2)) "*VALUES*";
drop view rule_v1;
create view rule_v1(x) as select * from (values(1,2)) v;
\d+ rule_v1
View "public.rule_v1"
Column | Type | Modifiers | Storage | Description
---------+---------+-----------+---------+-------------
x | integer | | plain |
column2 | integer | | plain |
View definition:
SELECT v.column1 AS x,
v.column2
FROM ( VALUES (1,2)) v;
drop view rule_v1;
create view rule_v1(x) as select * from (values(1,2)) v(q,w);
\d+ rule_v1
View "public.rule_v1"
Column | Type | Modifiers | Storage | Description
--------+---------+-----------+---------+-------------
x | integer | | plain |
w | integer | | plain |
View definition:
SELECT v.q AS x,
v.w
FROM ( VALUES (1,2)) v(q, w);
drop view rule_v1;

View File

@ -953,6 +953,8 @@ select * from only t1;
select * from only t1_1;
select * from only t1_2;
reset constraint_exclusion;
-- test various flavors of pg_get_viewdef()
select pg_get_viewdef('shoe'::regclass) as unpretty;
@ -1007,3 +1009,19 @@ ALTER RULE "_RETURN" ON rule_v1 RENAME TO abc; -- ON SELECT rule cannot be renam
DROP VIEW rule_v1;
DROP TABLE rule_t1;
--
-- check display of VALUES in view definitions
--
create view rule_v1 as values(1,2);
\d+ rule_v1
drop view rule_v1;
create view rule_v1(x) as values(1,2);
\d+ rule_v1
drop view rule_v1;
create view rule_v1(x) as select * from (values(1,2)) v;
\d+ rule_v1
drop view rule_v1;
create view rule_v1(x) as select * from (values(1,2)) v(q,w);
\d+ rule_v1
drop view rule_v1;