faufenger / sql-erd-employee-data

Design the tables to hold data in the CSVs, import the CSVs into a SQL database, and answer questions about the data

sql-challenge

It is a beautiful spring day, and it is two weeks since you have been hired as a new data engineer at Pewlett Hackard. The first major task is a research project on employees of the corporation from the 1980s and 1990s. All that remain of the database of employees from that period are six CSV files.

This assignment utilises:

• ERD skills through QuickDatabaseDiagrams
• CSV file importing to SQL platform PgAdmin4 with Postgress
  • CSV files found in DATA folder
  • schema to create tables found in schema.sql
• Querying the CVS data in PgAdmin4 to get sepcific results
  • query listed in query.sql along with corresponding code
• Juypter notebook for testing if data provided was ficticious material
  • Using sqlalchemy, matplotlib, pandas and numpy

ERD used to connect tables

Sample of Queries in PgAdmin4

Histogram of Salary Range for company

Bar Graph of Average salary by Title

Outcome

Upon reviewing the data, the data is found to be false.
In so much that it was fabricated by the company as a test and not actual company records.
The employee id we were given returned April Foolsday, as shown in the dataframe below