Practical SQL is a pragmatic guide to analysing data sets using SQL, the programming language that powers the world's most popular database applications. The book focuses on finding the story that a data set tells and discovering the information in data sets, using the PostgreSQL database as its primary tool. Practical SQL is ideal for those who need a tool to find meaning in data: A marketing department staffer analysing the results of a customer survey; a student analysing a data set as part of a research project; even a journalist building a data set to investigate a government agency.