In This Chapter
Getting familiar with relational databases and SQL
Designing great relational databases
Doing data science tasks with SQL functions
SQL, or Structured Query Language, is a standard for creating, maintaining, and securing relational databases. It's a set of rules that you can use to quickly and efficiently query, update, modify, add, or remove data from large and complex databases. You use SQL to do these tasks, rather than doing them using Python or Excel, because SQL is the simplest, fastest way to get the job done. It offers a very plain and standardized set of core commands and methods that are hard to mess up when performing these tasks. In this chapter, I introduce you to some basic SQL concepts and explain how you can use SQL to do cool things like query, join, group, sort, and even text-mine structured datasets.
Although you can use SQL to work with structured data that resides in relational database management systems, you can’t use standard SQL as a big-data–handling solution because you can’t handle big data using relational database technologies. Much more on big data and big data handling ...