Deciding on Attributes and Definitions

To create a database, it is necessary to define the data:

Name	The name of the person on file. Names can be separated as:
	Title Senator Dr. Mr.	First Battson Sarah Noah	Middle D. O.	Last Belfrie Bellam Pinyon	Extension Jr. Ph.D.
	This example uses First name and Last name.
Address	The mailing address. U.S. addresses can be separated as: Care-of name Corporation name Street number, Street name, Apartment number, Additional directions City State Zip Code This example uses Street Address, City, State, Zip code and Country.
Telephone Number	U.S. telephone numbers can be separated as:
	Area Code	Exchange	Number	Extension
	(714)	261	7425	100
	Telephone numbers can also be differentiated as: Home Work Cellular Pager Fax Modem
International telephone numbers are more difficult, because in addition to the two or three digit country code, each country has its own city and exchange codes, and a different way of displaying the groupings. This example uses phone number category and phone number.

Next, decide how each of these attributes are stored.

1	First Name	Person’s first name is a text string, stored as is.
2	Last Name	Person’s last name is a text string, stored as is.
3	Street Address	Street portion of the address is not limited to the length of any attribute, but for practical reasons assume that mailing labels have a limit of 30 characters across. If necessary, this can be MultiValued to have several address lines.
4	City	City portion of the address is a text string.
5	State	State portion of the address is the two digit state code for U.S. addresses.
6	Zip Code	Zip code portion of the address is the Zip + 4 code for U.S. addresses.
7	Country	Country portion of the address is assumed to be U.S.A. if null.
8	Phone Category	This describes the type of telephone associated with the phone number (for example, home phone, work phone, fax, cellular, auto cellular, pager, modem).
9	Phone Number	Telephone number is a seven digit number for numbers within the same area code, or a ten digit number for numbers outside the area code.
10	Item-ID	File-defining item correlative is set up to assign new item-IDs as sequential numbers.

The database attributes are further defined, and the size of our database is approximated as follows:

0	Item-ID	4
1	First name	8
2	Last name	8
3	Street address	15
4	City	15
5	State	2
6	Zip Code	5
7	Country	0
8	Phone category	2
9	Phone number	10
	Total	65

The phone category attribute may reference a phone category file to keep the categories homogeneous. Also, the phone category attribute can be a controlling attribute of the phone number attribute, and keep the category and number on a one to one correlation.