Data Normalization and Personal Trainer
Normalization is the process of creating a table design by assigning specific fields or attributes to each table in the database. Normalization is used to develop an overall database design that is simple, flexible, and free of data redundancy. There are four stages in the normalization process: 1) unnormalized design 2) first normal form (1NF) 3) second normal form (2NF) and 4) third normal form (3NF). The 3NF represents the best design because it avoids redundancy and data integrity problems that still can exist in the prior three forms. The unnormalized design form exist when the table contains a repeating group. A repeating group is asset of one or more fields that can occur any number of times in a single record, with each occurrence having different having different values. A table is said to be in 1NF when it does not contain a repeating group. A table is said to be in 2NF when it is in 1NF and if all fields that are not part of the primary key are functionally dependent on the entire primary key. Finally, a table is said to be in 3NF when it’s in 2NF and every nonkey filed depends on the key, the whole key, and nothing but the key.
Normalization is an important part of the system design phase for Personal Trainer Inc because it will assist in a successful database design. Without normalization the database system could be inaccurate, slow, inefficient, and may not produce the reports that Personal Trainer Inc expects. By normalizing the database it will minimize the amount of duplicate data stored in the database, it will organize the date so when Personal Trainer Inc modifies it they only have to make the change in one place, it will allow Personal Trainer Inc to access and modify the data quickly and efficiently without compromising the integrity of the data in storage, and it will arrange the data in a logical order.
These are proposed tables for Personal Trainer in 3NF
| MEMBER | Member_id, lname, fname, age, addr, phone_num, exp_date |
| CLASSES | Class_id, date, start_time, finish_time, location, cost |
| MERCHANDISE | Merchandise_id, description, size, color, price |
| INSTRUCTOR | Instructor_id, lname, fname, |
Tables with sample data for Personal Trainer Inc.
MEMBER
| Member_id | Lname | Fname | Age | Addr | Phone_num | Exp_date |
| 10001 | Smith | Robert | 35 | 340 Ridge Rd Raleigh, NC 27609 | 919-354-0934 | 11/2017 |
| 10002 | Williams | Ken | 20 | 10 Spoon Cir Durham, NC 27703 | 919-935-0035 | 03/2017 |
| 10003 | Schnell | Drew | 43 | 289 Forest Ln Raleigh, NC 27612 | 919-289-7260 | 12/2016 |
Classes
| Class_id | Date | Start_time | Finish_time | Location | Cost |
| Spin class | 12/04/2016 | 5:00pm | 6:00pm | Studio 1A | 175.00 |
| Dance fitness | 12/13/2016 | 7:00pm | 8:30pm | Studio 3 | 100.00 |
| Cardio boxing | 11/30/2016 | 4:30pm | 5:30pm | Studio 4B | 150.00 |
MERCHANDISE
| Merchandise_id | Description | Size | Color | price |
| 201 | UA shirt | Large | Red | 45.00 |
| 202 | Nalgene bottle | 48oz | Black | 20.00 |
| 203 | Gloves | Large | Blue/Black | 35.00 |
INSTRUCTOR
| Instructor_id | Lname | fname |
| 301 | Scott | Greg |
| 302 | Thompson | Bradley |
| 303 | Davis | Trent |
Personal Trainer 