Hello everybody,
It's been some days that I've started to use litesql and I
wish to pose a question.
Suppose I have to map family relationships between a
group of persons. I will use something like this to define my database:
<object name="Person">
<field name="name" type="string"/>
</object>
<relation id="Father" unidir="true">
<relate object="Person" limit="
many" handle="father"/>
<relate object="Person" limit="one"/>
</relation>
Then I can create the Person objects: Dad, Son1 and Son2 and then
I link them like this:
Son1.father().link(Dad)
Son2.father().link(Dad)
Now
I'm able to retrieve each son's father ( Son1.father().get() ), but what if I
want to retrieve every son linked to the Dad person ?
Is it possible in the
database I've just defined or I am forced to define explicity a second
relationship ( the 'Children' relationship ) ?
I pose this question because
if, as it seems, I need to define the second relationship, I find this
redundant (two relations, two tables: correct ?). I mean, if I would have to
create this relationship in a regular database, I would have done something
like this:
create table Dad ( id, name )
create table Son ( id, name, idDad )
Being able to retrieve the Father of each Son and, in the same time, the Sons
of each Father:
select idDad from Son where id = xxx
select * from Son where
idDad = yyy
Thank you
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