Re: BUG #10836: Rule with RETURNING claims incorrect type

On 7/2/14 3:05 PM, hoschiraffel@freenet.de wrote:
> In essence, I observe that when explicitly listing columns in a RETURNING
> statement of a rule, the type checking is somehow thrown off. When using the
> '*' all is fine. Please see below for a small example session that exhibits
> this bug.
>
> $ psql test
> psql (9.3.4)
> Type "help" for help.
>
> test=# \set VERBOSITY verbose
> test=# create table foobar (id int, info text);
> CREATE TABLE
> test=# create view test_me as select id as foo, info as bar from foobar;
> CREATE VIEW
> test=# create rule test_me_ins as on insert to test_me do instead insert
> into foobar values (new.foo,new.bar) returning (id,info);
> ERROR:  42P17: RETURNING list's entry 1 has different type from column
> "foo"
> LOCATION:  checkRuleResultList, rewriteDefine.c:682

You're actually only returning a single column.  RETURNING (id, info)
is the same as  RETURNING ROW(id, info), which is very different from
RETURNING id, info.  See
http://www.postgresql.org/docs/9.3/static/rowtypes.html, for example.

Note that this behaviour is the same as in SELECT lists;  SELECT (id,
info) FROM foobar;  will also only give you a single column.


.marko