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dmorales · Apr 13th, 2005, 9:40 AM

So I'm making my first database and was wondering if I could some quick advice? How normalized are my tables? Or are they at all?

-1 table with Clients and all their information.

-2 table with Work Orders and the clients they belong to.

-3 table wth white papers and which order they correspond with.

-4 table with contacts info which correspond with other contact field in clients.

I kow this isn't very detailed but maybe you can still give me some good advice.

big_k105 · Apr 13th, 2005, 10:11 AM

well it sounds like it is really setup well, im not sure what more i would personally do to make it better but i will think on it and see what i can come up with

java_roshan · Apr 13th, 2005, 2:10 PM

If u want to find that they are well normalize, try a few update, insert and delete commands and check whether they satisfy the conditions or constraints appropriately.

(In other words, just a component testing of your table)

Try the above, and may be then you might feel whether your tables are normalized or not

xavier · Apr 13th, 2005, 2:30 PM

Actualy it depends. It would probably help if you would write the problem as well, and what fields do your tables contain.
One example would be:
In your first table Clients, if you have FirstName and LastName in the same colomn, that's not good. If you have the Clients address in one column it will probabily not be good either because at some point u may want customers from only one city, or only one streat.

Also, if you have also the client's phone, maybe he has multiple phones. Now you would make another table Telephone with a foreign key that would reference the primary key in the Clients table, and a column Tel ... and so one ..

What i described will take you to the second normalization form. I'm learning now about these things ...

so i only know the basics .. kinda'

Oh, 4 tables ... are not that many ...maybe you should have another look at the problem. In the end it all depends on what u plan on doing with your database.

dmorales · Apr 13th, 2005, 3:12 PM

thanks xavier makes sense. So does that mean that I need to break up the database into as many tables as possible? (within reason of course)

I would think that the more information was broken up into manageable pieces (tables?) the easier it would be to query, edit, and maintain. Is this a correct assumption?

java_roshan · Apr 13th, 2005, 11:02 PM

It is a correct assumption but there are many other factors under consideration other than just simple normalization. Tables may be normalized uptil the second normal form or just upto the first normal form. One of the reasons, as mentioned in a book (PEARSON EDUCATION, ELMASRI/NAVATHE, Fundamentals of Database Management Systems, 4th edition) is for performance. You might just go through the references of their slides which is available at
ftp://ftp.aw.com/cseng/authors/elmasri/Dbase4e/

and download the "powerpoint.zip" file.

But the assumption is not always true, it may be true for say around 85-90% of times..(just a rough assumption!!!)

xavier · Apr 13th, 2005, 11:27 PM

U should really look at online tutorials. Try searching google for: " database normalization tutorial " - you also could look at this : http://dev.mysql.com/tech-resources/...alization.html It will give you a rough ideea about normalization.

All the best to you

Apr 13th, 2005, 9:40 AM	#1
dmorales Programmer Join Date: Feb 2005 Posts: 74 Rep Power: 4	database normalization So I'm making my first database and was wondering if I could some quick advice? How normalized are my tables? Or are they at all? -1 table with Clients and all their information. -2 table with Work Orders and the clients they belong to. -3 table wth white papers and which order they correspond with. -4 table with contacts info which correspond with other contact field in clients. I kow this isn't very detailed but maybe you can still give me some good advice. __________________ Lorem ipsum dolor sit amet...

Apr 13th, 2005, 10:11 AM	#2
big_k105 PFO Founder Join Date: Mar 2004 Location: Fargo, ND Posts: 1,650 Rep Power: 10	well it sounds like it is really setup well, im not sure what more i would personally do to make it better but i will think on it and see what i can come up with __________________ BIG K aka Kyle Programming Forums Kyle K Online Please do not PM or email me programming questions. Post them in the forums instead.

Apr 13th, 2005, 2:10 PM	#3
java_roshan Professional Programmer Join Date: Mar 2005 Location: Student of University of Mumbai, Maharashtra State, India Posts: 344 Rep Power: 4	If u want to find that they are well normalize, try a few update, insert and delete commands and check whether they satisfy the conditions or constraints appropriately. (In other words, just a component testing of your table) Try the above, and may be then you might feel whether your tables are normalized or not __________________ Visit: http://www.somaiya.edu

Apr 13th, 2005, 2:30 PM	#4
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	Actualy it depends. It would probably help if you would write the problem as well, and what fields do your tables contain. One example would be: In your first table Clients, if you have FirstName and LastName in the same colomn, that's not good. If you have the Clients address in one column it will probabily not be good either because at some point u may want customers from only one city, or only one streat. Also, if you have also the client's phone, maybe he has multiple phones. Now you would make another table Telephone with a foreign key that would reference the primary key in the Clients table, and a column Tel ... and so one .. What i described will take you to the second normalization form. I'm learning now about these things ... so i only know the basics .. kinda' Oh, 4 tables ... are not that many ...maybe you should have another look at the problem. In the end it all depends on what u plan on doing with your database. __________________ Don't take life too seriously, it's not permanent !

Apr 13th, 2005, 3:12 PM	#5
dmorales Programmer Join Date: Feb 2005 Posts: 74 Rep Power: 4	thanks xavier makes sense. So does that mean that I need to break up the database into as many tables as possible? (within reason of course) I would think that the more information was broken up into manageable pieces (tables?) the easier it would be to query, edit, and maintain. Is this a correct assumption? __________________ Lorem ipsum dolor sit amet...

Apr 13th, 2005, 11:02 PM	#6
java_roshan Professional Programmer Join Date: Mar 2005 Location: Student of University of Mumbai, Maharashtra State, India Posts: 344 Rep Power: 4	It is a correct assumption but there are many other factors under consideration other than just simple normalization. Tables may be normalized uptil the second normal form or just upto the first normal form. One of the reasons, as mentioned in a book (PEARSON EDUCATION, ELMASRI/NAVATHE, Fundamentals of Database Management Systems, 4th edition) is for performance. You might just go through the references of their slides which is available at ftp://ftp.aw.com/cseng/authors/elmasri/Dbase4e/ and download the "powerpoint.zip" file. But the assumption is not always true, it may be true for say around 85-90% of times..(just a rough assumption!!!) __________________ Visit: http://www.somaiya.edu

Apr 13th, 2005, 11:27 PM	#7
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	U should really look at online tutorials. Try searching google for: " database normalization tutorial " - you also could look at this : http://dev.mysql.com/tech-resources/...alization.html It will give you a rough ideea about normalization. All the best to you __________________ Don't take life too seriously, it's not permanent !

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