On Thu, May 6, 2010 at 3:23 PM, Andrew Dunstan <andrew@dunslane.net> wrote:
> And many places regard "select *" in anything other than throw-away queries
> as bad practice anyway. I have seen people get bitten by it over and over
> again, and I have worked at companies where it is explicitly forbidden in
> coding standards.
In terms of application queries I generally agree. However, I think
this rule does not apply to server side definitions, especially in
regards to views and/or composite types. There are cases where you
_want_ the view to be define as 'all fields of x'...In fact, it's
pretty typical IMNSHO. It may be possible to expose this behavior.
I'd like to see:
select * from foo -- and --
select (foo).*
exhibit different behaviors -- ().* is more a type operator, returning
all the fields of foo, than a field list expression. This gives us a
cool loophole to exploit for views that really want to be defined with
*:
create view particular_foos as select (foo).* from foo where something = true;
create view something_complex as select (foo).*, (func(foo.field)).*;
-- execute func() just one time please!
The something_complex case above is a real problem in how it behaves
currently -- sometimes without a hassle free workaround. Am I off my
rocker? :-) I've made this point many times (prob got annoying a long
time ago) but I'm curious if you guys agree...
merlin