SQL-Challenge - Employee Database

This is a research project on employees of the corporation at Pewlett Hackard from the 1980s and 1990s. The database of the employees is stored in 6 csv files.

Data Engineering/Data Modeling

Inspecting csv files and sketch out ERD Model of the tables. For data modeling http://www.quickdatabasediagrams.com is used.
Table schema created with primary keys, composite key, and foreign keys for uniquely identifying a row. Imported csv files into a SQL database.

Data Analysis

1. Listing details of each employee with employee number, last name, first name, sex, and salary.

2. Listing first name, last name, and hire date for employees who were hired in 1986.

3. Listing the manager of each department with department number, department name, the manager's employee number, last name, first name.

4. Listing the department of each employee with employee number, last name, first name, and department name.

5. Listing first name, last name, and sex for employees whose first name is "Hercules" and last names begin with "B"

6. Listing all employees in the Sales department, including their employee number, last name, first name, and department name.

7. Listing all employees in the Sales and Development departments, including their employee number, last name, first name, and department name.

8. In descending order, list the frequency count of employee last names, i.e., how many employees share each last name.