Database

19-Feb-12 5:06

Hi everyone,
I want to make a library project,I have made this model and I have a question is this a correct desgin for implementation or no

Main table is Books I have these fields on it
Book ID Bookname Title publish year description ISBN

Authors table
Book ID author name phone address email

publishers table
BookID publisher name phone address email

BookID's are primary key in this databse and I am going to use of it for relationship

is this a correct design and do I need to insert anything?

Thanks

Eddy Vluggen19-Feb-12 5:39

Eddy Vluggen

19-Feb-12 5:39

messages wrote:
question is this a correct desgin for implementation or no

Instead of having each design validated here, you could use the normalization-rules and validate it yourself.

Bastard Programmer from Hell Suspicious | :suss:

Hamid_RT19-Feb-12 5:53

Hamid_RT

19-Feb-12 5:53

could you help me ,please I have read normalization-rules I want only know is this correct or it has problem(I mean is your sentence).I have almost like this problem I want to know do I need to normalization-rules no?

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Eddy Vluggen19-Feb-12 6:09

Eddy Vluggen

19-Feb-12 6:09

Hamid. wrote:
I have almost like this problem I want to know do I need to normalization-rules no?

If you want a decent relational model, then it would be wise to normalize them, at least up to 3NF. You can "prove" that your model is in 1NF by checking the five conditions mentioned on the Wikipedia[^].

_{I know that you're looking for a yes/no answer, but that's not good enough. If things go wrong you're not helped much by shouting that "Eddy" told you that your model is right/wrong. You want to be able to defend your model, as opposed to taking the word of a stranger.}

Bastard Programmer from Hell Suspicious | :suss:

Luc Pattyn19-Feb-12 6:55

Luc Pattyn

19-Feb-12 6:55

I don't think "book ID" is a good name for the primary key of an authors table.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

messages19-Feb-12 17:22

19-Feb-12 17:22

Yeah I think ISBN is a good idea. Smile | :)

Mycroft Holmes19-Feb-12 12:08

Mycroft Holmes

19-Feb-12 12:08

Your structure is quite incorrect. Think about 1 to many and ask these questions.

Does a publisher publish only 1 book?
Does and Author ALWAYS only write 1 book?
Does a book ALWAYS have only 1 author.

Go follow Eddies suggestion, it will help you understand the basics.

Never underestimate the power of human stupidity
RAH

messages19-Feb-12 17:21

19-Feb-12 17:21

Thanks for your answer I have read wikipedia 1NF,....but how can I those rules in my project, I need to have a clear idea to write let me explain in this way
(1)we have some publishers
(2)we have some authors
publishers publish different books of different authors so we need to three tables(publisher,author and book) I guess that they should have a many to many relationship is it correct?
could you tell me please how can I implement relationships between these tables?
Thanks

Mycroft Holmes19-Feb-12 17:27

Mycroft Holmes

19-Feb-12 17:27

Now you are getting the idea.

You need Link tables
lnkPublisherBook
LinkID
BookID
PublisherID

lnkAuthorBook
LinkID
BookID
AuthorID

Never underestimate the power of human stupidity
RAH

messages19-Feb-12 19:40

19-Feb-12 19:40

Thanks for your help may I ask my questions in the future?

Mycroft Holmes19-Feb-12 20:03

Mycroft Holmes

19-Feb-12 20:03

Never stop asking questions, just make sure you have thought about the questions you are asking. ALWAYS do some research before dumping it into the forum, especially as you are learning. Almost every question you can come up with will have already been asked many times.

Never underestimate the power of human stupidity
RAH

messages20-Feb-12 0:54

20-Feb-12 0:54

Hi again
I have made this schema,is this correct(its my first question)

LogIn table
user_name(primary key) password AuthorID(Foreign key) PublisherID(foreign key)

Publishers table
publisherID(primark key) publisher name phone address (and other fields)

Authors table
AuthorID(primary key) Author name phone address publisherID(Foreign key) (and other fields)

Books Table
BookID(primary key) Book name Year Title (and other fields)

and its my second question I thought to make this table for AuthorBook

AuthorBook table
AuthorBookID(primary key) AuthorID(Foreign key) BookID(Foreign key)

Do I need to Foreign key in Authors table or Book tables?
Thanks

Jörgen Andersson20-Feb-12 3:02

Jörgen Andersson

20-Feb-12 3:02

Don't you think an author might publish different books via different publishers?

messages wrote:
Do I need to Foreign key in Authors table or Book tables?

You should always use foreign keys in your tables whenever possible. It lowers the risk of corruption.

BTW, you're having a good naming standard for your fields.

Light moves faster than sound. That is why some people appear bright, until you hear them speak.
List of common misconceptions

messages20-Feb-12 3:20

20-Feb-12 3:20

Thank you for your help so my code is good and I need only to insert foreign key to Authors,right?
Thanks again

Jörgen Andersson20-Feb-12 3:34

Jörgen Andersson

20-Feb-12 3:34

It's ok so far, but you're not ready yet.
To clarify what I mentioned in my previous message, is that I doubt that it's correct that the Authors table is having the field PublisherID in it. As an author might choose to publish different books at different publishers.
I would argue that you need another link table, the BookPublisher table.

Light moves faster than sound. That is why some people appear bright, until you hear them speak.
List of common misconceptions

Finding the Max value per group.

smcnulty20005-Mar-12 22:03

smcnulty2000

5-Mar-12 22:03

FYI.
In the world of libraries it is important to note that a book might be bought multiple times even for the same library.

Like when Stephen King comes out with a new book. The library might buy 2 hardback copies that will be kept for a long time, and then they might buy later a set of paperbacks that won't last as long.

So, not only do you need a books table but you also need a table called 'items' that track the existence of the multiple copies of the same book.

When someone checks out a book they are actually checking out an 'item'.

Is this for a real library with patrons or is it a personal library, or an exercise?
In my personal library I have some books where I have more than one copy. Each instance has a different reason for being bought twice but that isn't important.

If you are doing this for a real public library you might have more things to add. You might also have to study the world of MARC records.

http://en.wikipedia.org/wiki/MARC_standards[^]

_____________________________
A logician deducts the truth.
A detective inducts the truth.
A journalist abducts the truth.

Give a man a mug, he drinks for a day. Teach a man to mug...

Clark Kent12317-Feb-12 5:47

Clark Kent123

17-Feb-12 5:47

I am having such a hard time writing a SQL query. Can someone please look over this query and see where am I going wrong?

I will be using the XML elements to describe the table even though I am using SQL Server 2008 R2..

HTML

<vPSR>
 <ProjectID/>
 <ReportMonth Comment="2 digit Month. (MM)" />
 <ReportYear Comment="4 digit Year. (YYYY)" />
</vPSR>

Here is an example of the data that is listed.
ProjectID ReportMonth ReportYear
1000700 05 2008
1000700 06 2008
1000700 07 2008
1000700 12 2008
1000700 01 2009 <-- I want the query to find this! Even though the Month is not the max value, but the Year is the Max value.

Here is what I have so far. Where am I going wrong?

SQL

SELECT vPSR.ProjectID, vPSR.ReportMonth, vPSR.ReportYear
    FROM vPSR
    WHERE vPSR.ReportMonth =
        (SELECT MAX(ReportMonth)
            FROM vPSR AS f
            WHERE f.ProjectID = ProjectID
            AND ReportYear =
                (SELECT MAX(ReportYear)
                FROM vPSR AS k
                WHERE k.ProjectID = vPSR.ProjectID))
    ORDER BY vPSR.ProjectID ASC

I got the idea on how to write the above query here.[^] I don't understand it that well.

If you need me to clarify anything please do not hesitate to ask.

scottgp17-Feb-12 8:19

scottgp

17-Feb-12 8:19

I'm thinking that ReportMonth and ReportYear should instead have been a ReportDate with some sort of Date datatype. Since they're not, concatenating the two columns seems to work:

SQL

SELECT     ProjectID, reportMonth, reportYear
FROM         test
WHERE     (reportYear + reportMonth =
                          (SELECT     MAX(reportYear + reportMonth) AS Expr1
                            FROM          test AS b
                            WHERE      (ProjectID = ProjectID)))

Scott

Corporal Agarn17-Feb-12 8:36

Corporal Agarn

17-Feb-12 8:36

You could try something like

SELECT vPSR.ProjectID, vPSR.ReportMonth, vPSR.ReportYear
FROM vPSR 
INNER JOIN (
    SELECT ProjectID, MAX(reportYear + reportMonth) AS Expr1
    FROM vPSR 
    GROUP by ProjectID 
) AS v2 
ON vPSR.ProjectID = v2.ProjectID
    AND (vPSR.ReportYear + vPSR.ReportMonth) = v2.Expr1

Clark Kent12321-Feb-12 2:58

Clark Kent123

21-Feb-12 2:58

I whole heartedly agree about concatenating the ReportMonth + ReportYear columns together. That was another idea that I have been thinking about.

Thanks!