Question

Employee ID	First Name	Last Name	email	Title	Address	Extension	Department	Department ID	Hiring Date	Department Phone #
0001	John	Smith	jsmith	Accountant	1300 West st	5775	Accounting	2100	8/1998	407-366-5700
0002	Brian	Miller	badams	Admin Assistant	1552 Palm dr	5367	Human resource	2300	4/1995	407-366-5300
0003	James	Miller	miller	Inventory Manager	2713 Buck rd	5432	Production	2520	8/1998	407-366-5400
0004	John	Jackson	jackson_sam	Sales Person	433 tree dr	5568	Sales	2102	6/1997	407-366-5500
0005	Robert	Davis	Davis	Manager	713 corner st	5642	Production	2520	1/2001	407-366-5400
0006	Paul	Thompson	thompsonp	Market Analyst	205 Bridge dr	5744	Marketing	2101	5/2003	407-366-5600
0007	Sandy	Davis	SDavis	Manager	713 Corner st	5702	Accounting	2100	11/1999	407-366-5700

1. List the major entities identified in the table above

2. After examining the table carefully identify candidate keys. Remember from the lecture that a candidate key field has to be unique, but should not hold private information that might compromise person's identity. For example SSN is unique and can be used to determine student information, so it is a candidate key, but using SSN might compromise student security for that it will not be used as primary key. The combination of first name and last name is not unique and cannot be used as a candidate key. Once the candidate keys been identified, some will be as primary keys and will be used to normalize the table. To connect the tables, the primary key of one table can be used as a foreign key in the other.

Answer 1

=== (1) ===
Entities in the relation:
- Employee ID
- First Name
- Last Name
- email
- Title
- Address
- Extension
- Department
- Department ID
- Hiring Date
- Department Phone #

=== (2) ===
Candidate keys:

- Employee ID
- email
- Extension
- First Name, Last Name
- First Name, Title
- First Name, Address
- First Name, Department
- First Name, Department ID
- First Name, Hiring Date
- First Name, Department Phone #
- Last Name, Department
- Last Name, Department ID
- Last Name, Hiring date
- Last Name, Department Phone #
- Title, Department
- Address, Department
- Title, Hiring Date
- Address, Hiring Date
- Department, Hiring Date
- Department ID, Hiring Date
- Hiring Date, Department Phone #
- Address, Department Phone #
- Title, Department Phone #

Note:

- for the given data values, the first name and last name together forms a unique identifier, unlike the given explanation in the question. Any subsequent modification in the dadta should also be changed in the solution.

- Candidate keys represent the minimum combination of entities that can uniquely identify a tuple in the given relational data.