Error Types and Basic Debugging

When developing Web applications with PHP and MySQL, you end up with potential bugs in one of four or more technologies. You could have HTML issues, PHP problems, SQL errors, or MySQL mistakes. The first step in fixing any bug is finding its source.

HTML problems are often the least disruptive and the easiest to catch. You normally know there’s a problem when your layout is all messed up. Some steps for catching and fixing these, as well as general debugging hints, are discussed in the next section.