DA Assignment
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week4da72215.docxPlease take the database design below and post the database normalization diagrams (data dependency diagrams) that would go along with your model. Keep in mind, that when you are creating an ER model, you are almost always already in 3NF. This is just a sign that you created your initial model well.
Therefore, Don’t try and un-normalize your tables to try and show 1NF and 2NF just for the sake of showing each step. This exercise is designed to take what you developed in week 3 and allow you to create data dependency diagrams by working through the normal form steps and rules. As you go through this process, you may find additional normal form discrepancies that you may have missed in the design process. Please define all dependencies in your data dependency diagrams.
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1) Business Rules
Business rules gives an important classification to relationship, attributes and constraints in an entity an example of comphones solutions business rule is
Technician ------------------------Repairs----------------------Computer
Computer--------------------------creates----------------------Job card
Salesman -------------------------sells---------------------------Computer
Computer ----------------------received------------------------workshop
2) ER Model
price
saleid
date
price
compid
empid
computers
status
Sales
Sales/Repairs
Repairs
workshop
jobcardNo
empid
EmpId
EmpName
3) Sample Data (2-3 rows for each entity)
Computer
|
comp’d |
Status |
price |
|
Hp 7289 |
new |
150$ |
|
Toshiba satellite |
used |
75$ |
|
Acer 5758 |
new |
300$ |
Sales
|
saleid |
date |
price |
empid |
|
001 |
12/4/2015 |
150$ |
1 |
|
002 |
25/6/2015 |
75$ |
2 |
|
003 |
23/3/2015 |
300$ |
3 |
|
|
|
|
|
Repairs
|
empid |
JobcardNo |
|
1 |
18929 |
|
2 |
17882 |
|
3 |
28191 |
Workshop
|
empid |
EmpName |
|
1 |
Evans P |
|
5 |
Claire W |
|
7 |
Alex U |
Note: that in database design business rules would always be defined first and the ER model would be based on these rules. So, try to write the rules first but it might be an iterative process!
Please take the database design and post the database normalization diagrams (data dependency diagrams) that would go along with your model. Keep in mind, that when you are creating an ER model, you are almost always already in 3NF. This is just a sign that you created your initial model well.
Therefore, Don’t try and un-normalize your tables to try and show 1NF and 2NF just for the sake of showing each step. This exercise is designed to take what you developed in week 3 and allow you to create data dependency diagrams by working through the normal form steps and rules. As you go through this process, you may find additional normal form discrepancies that you may have missed in the design process. Please define all dependencies in your data dependency diagrams.
