help on table strucure doubt ???

Dear all,

I am preapring my last exam to MCSD.NEt (let you guess which none is the
last) and I use transcender test for that and I am actually face to a
situation where I do not catch the reason of a particular table
configuration. If you can help I will apreciate.

The scenario is as follow :
It is mention to identify the correct relation fro modeling the fact that
EACH book maybe writen by more that one author.

Possible choice was :
a - Create a Book parent entity and an Author child entity
b - Create a Book child entity and an Author parent entity
c - Create a Book and Author parent entities and an BookAuthor child entity
d - Create a Book and Author child entities and an BookAuthor parent entity

The correect answer is C and I am not understanding why.
For me I was selected A

Do you have any comment to help me catch why C and not A ?

thanks for your reply
regards
serge

=?Utf-8?B?Y2FsZGVyYXJh?=

my 2 cents:

Think on this:
Author Table:
ID,Author
1, John C
2, Ann D

Book table:
ID,Title
A,My Book
B,Their Book

Then, the BookAuthor:
Book,Author
A,1
B,1
B,2

It means that Author cannot be a child table from Book or viceversa because
the relationship as expressed in the scenario, it is many-to-many and a
separate table will accomplish this task.

In my example, the Book A, belongs to John C, and The Book B, belongs to
John C and Ann D.

Hope this helps
"calderara" <> wrote in message
news293F242-E9A2-4DAF-BF07-...
> Dear all,
>
> I am preapring my last exam to MCSD.NEt (let you guess which none is the
> last) and I use transcender test for that and I am actually face to a
> situation where I do not catch the reason of a particular table
> configuration. If you can help I will apreciate.
>
> The scenario is as follow :
> It is mention to identify the correct relation fro modeling the fact that
> EACH book maybe writen by more that one author.
>
> Possible choice was :
> a - Create a Book parent entity and an Author child entity
> b - Create a Book child entity and an Author parent entity
> c - Create a Book and Author parent entities and an BookAuthor child
> entity
> d - Create a Book and Author child entities and an BookAuthor parent
> entity
>
> The correect answer is C and I am not understanding why.
> For me I was selected A
>
> Do you have any comment to help me catch why C and not A ?
>
> thanks for your reply
> regards
> serge

Blackmetal

It is third normalization, and it allows you to have many-to-many
relationship without duplicates.
If A is ans, how can you build the model?

--
cheers,
RL
"calderara" <> wrote in message
news293F242-E9A2-4DAF-BF07-...
> Dear all,
>
> I am preapring my last exam to MCSD.NEt (let you guess which none is the
> last) and I use transcender test for that and I am actually face to a
> situation where I do not catch the reason of a particular table
> configuration. If you can help I will apreciate.
>
> The scenario is as follow :
> It is mention to identify the correct relation fro modeling the fact that
> EACH book maybe writen by more that one author.
>
> Possible choice was :
> a - Create a Book parent entity and an Author child entity
> b - Create a Book child entity and an Author parent entity
> c - Create a Book and Author parent entities and an BookAuthor child
> entity
> d - Create a Book and Author child entities and an BookAuthor parent
> entity
>
> The correect answer is C and I am not understanding why.
> For me I was selected A
>
> Do you have any comment to help me catch why C and not A ?
>
> thanks for your reply
> regards
> serge

Egghead

Thnaks for you reply...

But could it be also teh same thing with your 2 first tables by simply
adding BookID to aujto table and set primnary key to ID, bookID in AUthor
table ?

serge

"Blackmetal" wrote:

> my 2 cents:
>
> Think on this:
> Author Table:
> ID,Author
> 1, John C
> 2, Ann D
>
> Book table:
> ID,Title
> A,My Book
> B,Their Book
>
> Then, the BookAuthor:
> Book,Author
> A,1
> B,1
> B,2
>
> It means that Author cannot be a child table from Book or viceversa because
> the relationship as expressed in the scenario, it is many-to-many and a
> separate table will accomplish this task.
>
> In my example, the Book A, belongs to John C, and The Book B, belongs to
> John C and Ann D.
>
> Hope this helps
> "calderara" <> wrote in message
> news293F242-E9A2-4DAF-BF07-...
> > Dear all,
> >
> > I am preapring my last exam to MCSD.NEt (let you guess which none is the
> > last) and I use transcender test for that and I am actually face to a
> > situation where I do not catch the reason of a particular table
> > configuration. If you can help I will apreciate.
> >
> > The scenario is as follow :
> > It is mention to identify the correct relation fro modeling the fact that
> > EACH book maybe writen by more that one author.
> >
> > Possible choice was :
> > a - Create a Book parent entity and an Author child entity
> > b - Create a Book child entity and an Author parent entity
> > c - Create a Book and Author parent entities and an BookAuthor child
> > entity
> > d - Create a Book and Author child entities and an BookAuthor parent
> > entity
> >
> > The correect answer is C and I am not understanding why.
> > For me I was selected A
> >
> > Do you have any comment to help me catch why C and not A ?
> >
> > thanks for your reply
> > regards
> > serge
>
>
>

=?Utf-8?B?Y2FsZGVyYXJh?=

can I build the model with A as follow :

BOOK
Id,Title, AuthorID ( primary key on ID, AUthorID)

AUTHOR
Id,Name,BookId (primary key on Id,BookId)

serge

"Egghead" wrote:

> It is third normalization, and it allows you to have many-to-many
> relationship without duplicates.
> If A is ans, how can you build the model?
>
> --
> cheers,
> RL
> "calderara" <> wrote in message
> news293F242-E9A2-4DAF-BF07-...
> > Dear all,
> >
> > I am preapring my last exam to MCSD.NEt (let you guess which none is the
> > last) and I use transcender test for that and I am actually face to a
> > situation where I do not catch the reason of a particular table
> > configuration. If you can help I will apreciate.
> >
> > The scenario is as follow :
> > It is mention to identify the correct relation fro modeling the fact that
> > EACH book maybe writen by more that one author.
> >
> > Possible choice was :
> > a - Create a Book parent entity and an Author child entity
> > b - Create a Book child entity and an Author parent entity
> > c - Create a Book and Author parent entities and an BookAuthor child
> > entity
> > d - Create a Book and Author child entities and an BookAuthor parent
> > entity
> >
> > The correect answer is C and I am not understanding why.
> > For me I was selected A
> >
> > Do you have any comment to help me catch why C and not A ?
> >
> > thanks for your reply
> > regards
> > serge
>
>
>

=?Utf-8?B?Y2FsZGVyYXJh?=

Well, even though it works, the model does not comply fullest with
normalization.

Through my experience (and even here in the company I work) I have found
some of this models done by some other programmers which I ended up by
spliting the tables using a CrossReference AKA the many-to-many as the
propossed model.

"calderara" <> wrote in message
news:E9F11B9C-78C1-48E6-8541-...
> can I build the model with A as follow :
>
> BOOK
> Id,Title, AuthorID ( primary key on ID, AUthorID)
>
> AUTHOR
> Id,Name,BookId (primary key on Id,BookId)
>
> serge
>
> "Egghead" wrote:
>
>> It is third normalization, and it allows you to have many-to-many
>> relationship without duplicates.
>> If A is ans, how can you build the model?
>>
>> --
>> cheers,
>> RL
>> "calderara" <> wrote in message
>> news293F242-E9A2-4DAF-BF07-...
>> > Dear all,
>> >
>> > I am preapring my last exam to MCSD.NEt (let you guess which none is
>> > the
>> > last) and I use transcender test for that and I am actually face to a
>> > situation where I do not catch the reason of a particular table
>> > configuration. If you can help I will apreciate.
>> >
>> > The scenario is as follow :
>> > It is mention to identify the correct relation fro modeling the fact
>> > that
>> > EACH book maybe writen by more that one author.
>> >
>> > Possible choice was :
>> > a - Create a Book parent entity and an Author child entity
>> > b - Create a Book child entity and an Author parent entity
>> > c - Create a Book and Author parent entities and an BookAuthor child
>> > entity
>> > d - Create a Book and Author child entities and an BookAuthor parent
>> > entity
>> >
>> > The correect answer is C and I am not understanding why.
>> > For me I was selected A
>> >
>> > Do you have any comment to help me catch why C and not A ?
>> >
>> > thanks for your reply
>> > regards
>> > serge
>>
>>
>>

Blackmetal

I forgot to add:

I've felt really ****ed off by this type of programming, because sometimes,
I had to make a fix to someone else's work...and simply the way the queries
are built are so messy and so complex without reason that I ended up by
re-writting the queries or modify the schema of the involved tables.

"Blackmetal" <> wrote in message
news:...
> Well, even though it works, the model does not comply fullest with
> normalization.
>
> Through my experience (and even here in the company I work) I have found
> some of this models done by some other programmers which I ended up by
> spliting the tables using a CrossReference AKA the many-to-many as the
> propossed model.
>
> "calderara" <> wrote in message
> news:E9F11B9C-78C1-48E6-8541-...
>> can I build the model with A as follow :
>>
>> BOOK
>> Id,Title, AuthorID ( primary key on ID, AUthorID)
>>
>> AUTHOR
>> Id,Name,BookId (primary key on Id,BookId)
>>
>> serge
>>
>> "Egghead" wrote:
>>
>>> It is third normalization, and it allows you to have many-to-many
>>> relationship without duplicates.
>>> If A is ans, how can you build the model?
>>>
>>> --
>>> cheers,
>>> RL
>>> "calderara" <> wrote in message
>>> news293F242-E9A2-4DAF-BF07-...
>>> > Dear all,
>>> >
>>> > I am preapring my last exam to MCSD.NEt (let you guess which none is
>>> > the
>>> > last) and I use transcender test for that and I am actually face to a
>>> > situation where I do not catch the reason of a particular table
>>> > configuration. If you can help I will apreciate.
>>> >
>>> > The scenario is as follow :
>>> > It is mention to identify the correct relation fro modeling the fact
>>> > that
>>> > EACH book maybe writen by more that one author.
>>> >
>>> > Possible choice was :
>>> > a - Create a Book parent entity and an Author child entity
>>> > b - Create a Book child entity and an Author parent entity
>>> > c - Create a Book and Author parent entities and an BookAuthor child
>>> > entity
>>> > d - Create a Book and Author child entities and an BookAuthor parent
>>> > entity
>>> >
>>> > The correect answer is C and I am not understanding why.
>>> > For me I was selected A
>>> >
>>> > Do you have any comment to help me catch why C and not A ?
>>> >
>>> > thanks for your reply
>>> > regards
>>> > serge
>>>
>>>
>>>
>
>

Blackmetal

Holy Crap...I'm keep on forgetting things...

And precisely, in a MS exam this is a very valid point too, because even
your model worked, according the Exam, it would be a bad score because
that's not the best solution, and many of us might have failed in questions
in our exams too, but that's the good thing about learning.

"Blackmetal" <> wrote in message
news:...
>I forgot to add:
>
> I've felt really ****ed off by this type of programming, because
> sometimes, I had to make a fix to someone else's work...and simply the way
> the queries are built are so messy and so complex without reason that I
> ended up by re-writting the queries or modify the schema of the involved
> tables.
>
> "Blackmetal" <> wrote in message
> news:...
>> Well, even though it works, the model does not comply fullest with
>> normalization.
>>
>> Through my experience (and even here in the company I work) I have found
>> some of this models done by some other programmers which I ended up by
>> spliting the tables using a CrossReference AKA the many-to-many as the
>> propossed model.
>>
>> "calderara" <> wrote in message
>> news:E9F11B9C-78C1-48E6-8541-...
>>> can I build the model with A as follow :
>>>
>>> BOOK
>>> Id,Title, AuthorID ( primary key on ID, AUthorID)
>>>
>>> AUTHOR
>>> Id,Name,BookId (primary key on Id,BookId)
>>>
>>> serge
>>>
>>> "Egghead" wrote:
>>>
>>>> It is third normalization, and it allows you to have many-to-many
>>>> relationship without duplicates.
>>>> If A is ans, how can you build the model?
>>>>
>>>> --
>>>> cheers,
>>>> RL
>>>> "calderara" <> wrote in message
>>>> news293F242-E9A2-4DAF-BF07-...
>>>> > Dear all,
>>>> >
>>>> > I am preapring my last exam to MCSD.NEt (let you guess which none is
>>>> > the
>>>> > last) and I use transcender test for that and I am actually face to a
>>>> > situation where I do not catch the reason of a particular table
>>>> > configuration. If you can help I will apreciate.
>>>> >
>>>> > The scenario is as follow :
>>>> > It is mention to identify the correct relation fro modeling the fact
>>>> > that
>>>> > EACH book maybe writen by more that one author.
>>>> >
>>>> > Possible choice was :
>>>> > a - Create a Book parent entity and an Author child entity
>>>> > b - Create a Book child entity and an Author parent entity
>>>> > c - Create a Book and Author parent entities and an BookAuthor child
>>>> > entity
>>>> > d - Create a Book and Author child entities and an BookAuthor parent
>>>> > entity
>>>> >
>>>> > The correect answer is C and I am not understanding why.
>>>> > For me I was selected A
>>>> >
>>>> > Do you have any comment to help me catch why C and not A ?
>>>> >
>>>> > thanks for your reply
>>>> > regards
>>>> > serge
>>>>
>>>>
>>>>
>>
>>
>
>

Blackmetal

Your model doesn't allow many-to-many modeling with any real sense of
correctness. It's horribly denormalized.

Let's suppose I had book "How to pass 70-300", and it was writen by
"Author1", "Author2", "Author3".
Let's also say, "Author1" wrote "How to fail 70-300"

What values would be in the two tables?

The closes I can come is:
ID 1 = "How to pass 70-300"
ID 2 = "How to fail 70-300"

ID 3 = "Author1"
ID 4 = "Author2"
ID 5 = "Author3"

Which would give
[Book]
1, How to pass 70-300, 3
1, How to pass 70-300, 4
1, How to pass 70-300, 5
2, How to fail 70-300, 3

[Author]
3, Author1, 1
3, Author1, 2
4, Author2, 1
5 Author3, 1

Clearly, this schema isn't the best answer available.

--
Chris Mullins, MCSD.NET, MCPD:Enterprise, Microsoft C# MVP
http://www.coversant.com/blogs/cmullins

"calderara" <> wrote in message
news:E9F11B9C-78C1-48E6-8541-...
> can I build the model with A as follow :
>
> BOOK
> Id,Title, AuthorID ( primary key on ID, AUthorID)
>
> AUTHOR
> Id,Name,BookId (primary key on Id,BookId)
>
> serge
>
> "Egghead" wrote:
>
>> It is third normalization, and it allows you to have many-to-many
>> relationship without duplicates.
>> If A is ans, how can you build the model?
>>
>> --
>> cheers,
>> RL
>> "calderara" <> wrote in message
>> news293F242-E9A2-4DAF-BF07-...
>> > Dear all,
>> >
>> > I am preapring my last exam to MCSD.NEt (let you guess which none is
>> > the
>> > last) and I use transcender test for that and I am actually face to a
>> > situation where I do not catch the reason of a particular table
>> > configuration. If you can help I will apreciate.
>> >
>> > The scenario is as follow :
>> > It is mention to identify the correct relation fro modeling the fact
>> > that
>> > EACH book maybe writen by more that one author.
>> >
>> > Possible choice was :
>> > a - Create a Book parent entity and an Author child entity
>> > b - Create a Book child entity and an Author parent entity
>> > c - Create a Book and Author parent entities and an BookAuthor child
>> > entity
>> > d - Create a Book and Author child entities and an BookAuthor parent
>> > entity
>> >
>> > The correect answer is C and I am not understanding why.
>> > For me I was selected A
>> >
>> > Do you have any comment to help me catch why C and not A ?
>> >
>> > thanks for your reply
>> > regards
>> > serge
>>
>>
>>

Chris Mullins [MVP]

yes thats for sure I undersatnd your pain in such situation. I guess similar
situation with programmers who did not follow guide line that I was
describing and then correct they< work and loosing time...

But for my case actually I am not an SQL guy, it just come time to time
during dayly work but I am not a specialist on the way to organise tables and
so on. And thatt is the reason I was stuck in this situation when learning my
final exam...And when I do not cacth the idea of doing it in this way and not
the other, I will stick on it for days...

Now your answer it clear now for me, the way I was saying works, but it is
not the normal way of snormalization...

Thnaks for your reply
regards
serge

"Blackmetal" wrote:

> I forgot to add:
>
> I've felt really ****ed off by this type of programming, because sometimes,
> I had to make a fix to someone else's work...and simply the way the queries
> are built are so messy and so complex without reason that I ended up by
> re-writting the queries or modify the schema of the involved tables.
>
> "Blackmetal" <> wrote in message
> news:...
> > Well, even though it works, the model does not comply fullest with
> > normalization.
> >
> > Through my experience (and even here in the company I work) I have found
> > some of this models done by some other programmers which I ended up by
> > spliting the tables using a CrossReference AKA the many-to-many as the
> > propossed model.
> >
> > "calderara" <> wrote in message
> > news:E9F11B9C-78C1-48E6-8541-...
> >> can I build the model with A as follow :
> >>
> >> BOOK
> >> Id,Title, AuthorID ( primary key on ID, AUthorID)
> >>
> >> AUTHOR
> >> Id,Name,BookId (primary key on Id,BookId)
> >>
> >> serge
> >>
> >> "Egghead" wrote:
> >>
> >>> It is third normalization, and it allows you to have many-to-many
> >>> relationship without duplicates.
> >>> If A is ans, how can you build the model?
> >>>
> >>> --
> >>> cheers,
> >>> RL
> >>> "calderara" <> wrote in message
> >>> news293F242-E9A2-4DAF-BF07-...
> >>> > Dear all,
> >>> >
> >>> > I am preapring my last exam to MCSD.NEt (let you guess which none is
> >>> > the
> >>> > last) and I use transcender test for that and I am actually face to a
> >>> > situation where I do not catch the reason of a particular table
> >>> > configuration. If you can help I will apreciate.
> >>> >
> >>> > The scenario is as follow :
> >>> > It is mention to identify the correct relation fro modeling the fact
> >>> > that
> >>> > EACH book maybe writen by more that one author.
> >>> >
> >>> > Possible choice was :
> >>> > a - Create a Book parent entity and an Author child entity
> >>> > b - Create a Book child entity and an Author parent entity
> >>> > c - Create a Book and Author parent entities and an BookAuthor child
> >>> > entity
> >>> > d - Create a Book and Author child entities and an BookAuthor parent
> >>> > entity
> >>> >
> >>> > The correect answer is C and I am not understanding why.
> >>> > For me I was selected A
> >>> >
> >>> > Do you have any comment to help me catch why C and not A ?
> >>> >
> >>> > thanks for your reply
> >>> > regards
> >>> > serge
> >>>
> >>>
> >>>
> >
> >
>
>
>

=?Utf-8?B?Y2FsZGVyYXJh?=