Sams Teach Yourself PHP in 24 Hours, Third Edition

Summary

In this hour and the previous hour, you learned different ways of saving state in a stateless protocol. All methods use some combination of cookies and query strings, sometimes combined with the use of files or databases. These approaches all have their benefits and problems.

A cookie is not intrinsically reliable and cannot store much information. On the other hand, it can persist over a long period of time.

Approaches that write information to a file or database involve some cost to speed that might become a problem on a popular site. Nonetheless, a simple ID can unlock large amounts of data stored on disk.

A query string is unlikely to persist as a cookie will and looks ugly in the location window. Even so, it can pass relatively ...