Collection Object

[Philip Mötteli]

Am 31.07.2006 um 19:24 schrieb Ruslan Zasukhin:
> On 7/31/06 7:33 PM, "Philip Mötteli"  
> <philip.moetteli at econophone.ch> wrote:
>
>>> Also we can want do
>>>
>>>     SELECT RecID, f3
>>>     FROM  NSSet
>>>     WHERE f3.contains( 7 )
>>>
>>>         ---------------------------------------------
>>> cursor      RecID    f3
>>>         ----------------------------------------------
>>>             1       { 2, 3, 7, 9, 12 }
>>>             3       { 4, 7, 11, 13, 24, 32, 45, 68 }
>>>
>>> Or you think about something else?
>>
>> Two cases:
>>
>> 1.) SELECT RecID
>> FROM NSSet
>> WHERE RecID=1 AND f3.contains(7)
>>
>> This would merely return a BOOL.
>
> Then the same with EXISTS

Yes.


>> 2.) SELECT f3
>> FROM NSSet
>> WHERE RecID=1 AND f3.*.name='Ruslan'
>>
>> Actually searching in the records referenced by the OIDs in f3.
>>
>>
>>> AS RESULT of search we must find NSSet instances, right ?
>>
>> In case 2: Yes. In case 1: NO, just a BOOL.
>
> SELECT f3
> FROM NSSet
> WHERE
>     RecID = 1 AND
> ..??..
>     SELECT
>     FROM Ti
>     WHERE Ti.name IN NSSet.f3
>
>
> Hmm, it seems SQL do not have query type which can do similar thing ..
> OF course we can have low level API methods...
> But SQL also is in interest
>
> It needs to think about this deeply. You have touch very  
> interesting issue.
>     mix of Arrays, Links, Ptrs, ...

Definitely. Do others already have solved this problem?


> On the other hand may be inheritance way is the most easy overall and
> natural here ...

I just don't see, how you want to do that.
There's inheritance in EOF, but they don't solve the collection  
problem with that.


Re
Phil