Question

1. Assume the below three tables are the only three tables that exist in a relational database. Label any Primary (PK) and Foreign (FK) Keys you see in the tables. Also highlight any rules violations that you see, then below the tables explain the violation using language of the database rules.

Employee_Table:

First	Last	Emp_ID	Ann_Pay	Ph_No.
Ann	Smith	80001	120,000.00	555-555-7563
Sara	Yeld	80002	61,000.00	555-555-7897
Lorry	Cox		120,001.00	555-555-1151 555-555-9877

Sales_Table:

Inv_Date	Inv_No.	Cust_ID	Emp_ID_Sales	Amt.	Cust_Age.
1/1/19	1001	1685	80002	55,987.22	18
1/4/19	1002	1251	80001	21,668.18	54
1/21/19	1003	1301	80002	35,696.71	43

Customer_Table:

Phone	LastN	FirstN	ID
555-555-1423	Stone	Candice	1685
555-555-6163	Alves	Delilah	1301

Answer 1

In Employee_Table :

Primary key =  Emp_ID

Foreign key = No foreign key

Violations :

Here primary key is  Emp_ID but here all the row is not prasent key so that is a big violations .

Sales_Table:

Primary key = Inv_No

Foreign key =  Emp_ID_Sales and  Cust_ID

Violations :

Here is no violence is prasent .

Customer_Table:

Primary key = ID

Foreign key =  No foreign key

Violations :

Here is no violence is prasent .