Re: Object-relational impedence

S Perryman <q_at_q.net> wrote in news:fqoenv$fo4$1_at_news.datemas.de:

> Yagotta B. Kidding wrote:
>

>> S Perryman <q_at_q.com> wrote in news:fqn0ir$mdg$1_at_aioe.org:

>>>boolean f(Tuple t) { return (t.x = 123) ; }

>>>Set<Tuple> S ;

>>>Set<Tuple> t = S.match(f) ; // or match(S,f) if one prefers

>>>1. How is the above not "set-oriented" ??

>>>A set is given as input to a match operation which produces a
>>>set as output.

>>>2. I have no idea whatsoever *how* S performs the match by
>>>    looking at the above.

>> 'Match' is cool,  but what about more interesting operations like 
>> 'project(join(R1,R2)), R1.a1, R2.b3)'  where R1 is a set of
>> <c,a1,a2,a3> tuples and R2 is a set of <c, b1,b2,b3> tuples  ?  How
>> do you express that in your fav OO language ?

Does "the semantics of "joins" are an issue for OO" mean that relational joins cannot be implemented in principle in an object-oriented way ?

>
>
> Regards,
> Steven Perryman
>
Received on Thu Mar 06 2008 - 16:06:29 CET