Chapter 12: Relationships

As you’ve worked through the construction of the Internet Joke Database website, you’ve had opportunities to explore most aspects of Structured Query Language (SQL). You’ve been introduced to many SQL commands now—from the basic form of a CREATE TABLE query to the two syntaxes of INSERT queries.

In Chapter 5, I showed you how to perform basic JOINs using SQL to fetch data from more than one table at a time. A lot of the time, you’ll come across situations where you want to do this—for example, finding information about an author as well as all the jokes they’ve posted, or finding a category and all the jokes that reside inside it.

SQL JOIN is one of many solutions to this problem. Although there are performance advantages ...

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