You are required to develop a simple database application for a small recruiting firm that wishes to keep track of all the employees at the firm; storing details about their name, phone numbers, hiredate, Gender, Date of Birth, Salary, and Commission. The firm has many departments and there are 5 to 20 employees in each department. The department information includes department name, description and total number of employees in that department. The company also provides vehicles for some of its employees. An employee maybe allocated one car. To ensure timely maintenance of vehicle, the company would like to store the following details of the vehicle: make, model, next_maintenance_date. Each employee has a position (manager, accountant, administrator, clerk, HR employee, etc.). Various allowances are allocated to each position. For example, the managers have fuel allowance, house allowance, social allowance and managers allowance. On the other hand, the administrators have house allowance and social allowance. Clerks and HR employees have social allowance and uniform allowance. The name and description of each allowance needs to be stored. The database keeps track of all Projects in the organization. Each department is assigned to one or more project. Project can be assigned to one or more department (Interdisciplinary projects). The HR Employee has his own credentials to login into the system to manipulate the database. The credentials are stored in a table (Login). You will also need a table to store transactions (Transaction Date/Time, User Name, Position, and Employee Number). The system must store employees' grades. Each employee will have a grade (Example A, B, C). The grade should have a predefined salary range. The system must store information about employee's overtime base on night or day shift, number of working hours, and grade. An employee may or may not work overtime. The calculation of overtime is based on Hourly pay rate per grade * Number of working Hours* Day or Night Shift. The maximum number of hours for overtime is 8 hours. Night time shift pay is twice the Day time shift pay. The hourly pay rate is based on the Grade. Example (Grade A receives $200, Grade B Receives $150 and So on). You need to have the following constraints in your system: Primary and foreign keys. The employee's salary should be between the grade range (Example: Grade A - Salary between 30000- 50000). Employee's phone number, Hiredate, Date of Birth should not be empty. The age should be between 18 and 60. Vehicle next maintenance is within 3 month of current date. Each position should not exceed the predefined allowances. The System will need a constraint for Gender ('M','F'). The Username must be Unique in Table Login. Mandatory fields must not be NULL. I did this, and i need this a. Mapping ERD to Relational Schema. b. Adding Foreign Keys. c. Resolve any M:N relationship between the entities.