Relational databases are a mature and ubiquitous technology that is used to store and query data. Relational databases store data in the form of relations, also known as tables, which allow for an excellent combination of performance, efficiency, and ease of use. SQL is the language used to access relational databases. SQL is a declarative language that allows users to focus on what to create, as opposed to how to create it. SQL supports many different data types, including numeric data, text data, and even data structures.
When querying data, SQL allows a user to pick which fields to pull, as well as how to filter the data. This data can also be ordered, and SQL allows for as much or as little data as we need to be pulled. Creating, updating, and deleting data is also fairly simple and can be quite surgical.
Now that we have reviewed the basics of SQL, we will discuss how SQL can be used to perform the first step in data analytics, cleaning, and the transformation of...