Re: Outer join construction step :strange results

> Oliveiros d'Azevedo Cristina wrote:
>> Howdy, Cedric .
>>
>> Before analysing this problem of yours further, I 'd like you to
>> kindly clarify me some points, please
>>
>>
>>
>>>
>>> I have table following tables T0,T1,T2,T3, T1T2
>>> with
>>> -T0(id, fk_T1)
>>> -T1(id )
>>> -T2(id, fk_T3)
>>> -T1T2(fk_T1,fk_T2)
>>> -T3 (id)
>>>
>>> The table T0 represents sets of T1 items.
>>> The table T1 represents items.
>>> The table T3 represents property types.
>>> The table T2 represents represents property values of a specific type.
>>>
>>
>>
>> T0.id is not a primary key, is it?
> all columns with id are Primary keys
> all columns with fk_T1 are foreign keys

Can you specify a little more how you represent T1 item sets with this data
model?
What exactly represents one row from table T0? A pair (id, fk_T1) ? A set
with just one element?

Best,
Oliveiros