An independent project performed to apply SQL knowledge to a data science problem.

After completing the codecademy course for SQL and reading through w3schools documentation on SQL, I decided to apply what I'd learned via a small project.

The project provides access to a small sample data set and are asked to answer some questions ranging in difficulty from easy to difficult.

The data set is located here and consists of the following tables:

• employees table stores employees data such as employee id, last name, first name, etc. It also has a field named ReportsTo to specify who reports to whom.
• customers table stores customers data.
• invoices & invoice_items tables: these two tables store invoice data. The invoices table stores invoice header data and the invoice_items table stores the invoice line items data.
• artists table stores artists data. It is a simple table that contains only artist id and name.
• albums table stores data about a list of tracks. Each album belongs to one artist. However, one artist may have multiple albums.
• media_types table stores media types such as MPEG audio and AAC audio file.
• genres table stores music types such as rock, jazz, metal, etc.
• tracks table store the data of songs. Each track belongs to one album.
• playlists & playlist_track tables: playlists table store data about playlists. Each playlist contains a list of tracks. Each track may belong to multiple playlists. The relationship between the playlists table and tracks table is many-to-many. The playlist_track table is used to reflect this relationship.

Added all of my responses to the following prompts under the basic folder in this repository.

• Which tracks appeared in the most playlists? how many playlist did they appear in?

• Which track generated the most revenue? which album? which genre?

• Which countries have the highest sales revenue? What percent of total revenue does each country make up?

• How many customers did each employee support, what is the average revenue for each sale, and what is their total sale?

• Do longer or shorter length albums tend to generate more revenue?

• How much revenue is generated each year, and what is its percent change 1 from the previous year?

Mini project completed in four hours on Mac OS, using DB Browser for SQLite.