In this research project data modeling, engineering, and analyis were peformed on employees of a corporation from the 1980s and 1990s. All that remain of the database of employees from that period were six CSV files.

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Data Modeling

The first step was to inspect the CSV's, design tables, and sketch them out in an ERD. To facilitate this first step, Quick-DBD was used.

Data Engineering

Next, the information used to create the ERD was used to build a table schema for each of the six CSV files. In this step, data types, primary keys, foreign keys, and other constraints were identified.

Data Analysis

Finally, the CSV's were imported into a SQL database (PostgreSQL) where schema queries were run to answer questions about the data.

Below are the individual schema queries that were run once the individual data sets were combined.

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List of details for each employee:

• Employee Number
• Last Name
• First Name
• Sex
• Salary

Employees hired in 1986:

• First Name
• Last Name
• Hire Date

The manager of each department with the following details:

• Department Number
• Department Name
• Manager's Employee Number
• Last Name
• First Name

The department of each employee with the following details:

• Employee Number
• Last Name
• First Name
• Department Name

Details for employees whose first name is "Hercules" and last names begin with "B":

• First Name
• Last Name
• Sex

List of all employees in the Sales department, including the following details:

• Employee Number
• Last Name
• First Name
• Department Name

List of all employees in the Sales and Development departments, including the following details:

• Employee Number
• Last Name
• First Name
• Department Name

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