An SQL database provides a powerful solution to many problems that arise in web-based applications. In addition to storing text and image data, you can use SQL to assist in building user interfaces. You can also use SQL to process your web logs, generate XML, and store the results of web scraping.
Despite these benefits, however, it can be dangerous to use SQL in online applications. This chapter includes advice on how to exploit an SQL injection vulnerability and how to avoid becoming a victim of such an attack.