As I explained in Chapter 11, one of the major strengths of a relational database is the ability to link data in different tables by using the primary key from one table as a foreign key in another table. The
phpsols database has two tables:
blog. It's time to add some more and join them, so you can assign categories to blog entries and associate images with individual articles.
You don't join multiple tables physically, but through SQL. Often, you can join tables by identifying a direct relationship between primary and foreign keys. In some cases, though, the relationship is more complex and ...