On Wed, Oct 22, 2014 at 11:21 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote: > Hi > > with new functions row_to_json(b), there is more often usage of ROW > constructor. Using names in fields is relative difficult. Because ROW has > special clause in parser, I am thinking so we can enable labeling inside ROW > constructor > > so instead currently supported: > > select row_to_json(r) from (select 10 as a, 20 as b) r; > > users can to write: > > select row_to_json(row(10 as a,20 as b)); > > labeling will be enabled "only" inside ROW constructor. I don't propose > enable it everywhere. > > What do you think about it?
we can replace a expr_list by target_list. I know only so it doesn't enforce a problems with gramatic - bison doesn't raise any warning.
*) Are we ok with SQL standard
SQL standard doesn't think named attributes in row - so it is out of range ANSI. But it is not in conflict with standard. "AS name" is used more in SQL/MM, SQL/XML -- and function named parameters has different syntax "parameter_name <= value" - I checked it against SQL99.
*) Do you think this (or some similar variant) would work?
select row_to_json(row(foo.*)) from foo;
It looks like independent feature and can work too - it is more natural for user.