This chapter introduces relational databases as a way to structure and organize complex data sets. After introducing the purpose and format of relational databases, it describes the syntax for interacting with them using
R. By the end of the chapter you will be able to wrangle data from a database.
13.1 An Overview of Relational Databases
Simple data sets can be stored and loaded from
.csv files, and are readily represented in the computer’s memory as a data frame. This structure works great for data that is structured just as a set of observations made up of features. However, as data sets become more complex, you run against some limitations.
In particular, your data may not be structured in a way that it can easily ...