Re: Something new for the New Year (2008).

On Jan 7, 6:29 pm, JOG <j..._at_cs.nott.ac.uk> wrote:
>
> Anyhow, here is an example for you:
>
> 1) UK is in Europe => (country:UK, continent:Europe)
> 2) Canada is in N. America => (country:Canada, continent:N.America)
> 3) Bob is 30 and lives in the UK => (name:Bob, age:30, country:UK)
> 4) Sarah is 28 and lives in Canada => (name:Bob, age:30, country:UK)
> 5) Bob is Married to Sarah => (husband:Bob, bride:Sarah)
>
> According to your definitions (1) and (2) are normal propositions (3)
> and (4) are PKFK and (5) is a JT. Your AL structure corresponds to no
> statement of fact that I can think of. Regards, J.
>
1. Statement of Facts, Example 1:

2 sets if propositions (i.e., 2 tables: Adult, Child)

Bob is a male child, age 15		=> (childname:Bob,sex:male,age:15)
Carol is a female child, age 13		=> (childname:Carol,sex:female,age:
13)
Dee is a female child, age 8		=> (childname:Dee,sex:female,age:8)

Al is father of Bob			=> (father:Al,child:Bob)
Al is father of Carol			=> (father:Al,child:Carol)
Al is father of Dee			=> (father:Al,child:Dee)

2. Now, although Al is father of Bob, Carol and Dee, only Bob and
     Carol are siblings. Dee is a child of a 2nd marriage. We want
     to capture the fact that Bob and Carol are siblings, but Bob
     and Dee (and Carol and Dee) are half-siblings. So, instead of
     the JT (i don't know what you call it), I propose the following
     Aggregate and Link:

--
Al is the father in family unit 1	=> (familyunit:1,familyfather:Al)
Al is the father in family unit 2	=> (familyunit:2,familyfather:Al)

Link:
--
Bob is a child in family unit 1	=> (familychild:Bob,familyunit:1)
Carol is a child in family unit 1	=> (familychild:Carol,familyunit:1)
Dee is a child in family unit 2	=> (familychild:Dee,familyunit:2)

You don't explain how you formulate queries, but the sense of the
   following should be clear:

Who are the siblings of B?
   The siblings of Bob are the childs of the family unit
      in which Bob is a child, not including Bob.
Who are the half-siblings of Bob?
   The half-siblings of Bob are the childs of any family
      unit with the same father as the familyfather of the
      family unit in which B is a child, not including
      the family unit in which B is a child.
Who is the father of B?
   The father of B is the familyfather of the familyunit in
      which B is a child.

OK?