Head First PHP & MySQL

Appendix A. Leftovers: The Top Ten Topics (we didn’t cover)

Even after all that, there’s a bit more. There are just a few more things we think you need to know. We wouldn’t feel right about ignoring them, even though they only need a brief mention. So before you put the book down, take a read through these short but important PHP and MySQL tidbits. Besides, once you’re done here, all that’s left are a couple short appendices... and the index... and maybe some ads... and then you’re really done. We promise!

#1. Retrofit this book for PHP4 and mysql functions

With the exception of XML functions in Chapter 13, most of the code in this book will run on PHP 4 servers with only a little modification. We’ve used the mysqli family of functions in this book, which are only available in PHP 4.1 and later, and since the library has to be manually installed, some servers won’t support mysqli.

Mysqli functions are generally faster, but this really only begins to matter when your database becomes huge. Small or average databases won’t be perceptibly slower with the older mysql functions. This section is designed to tell you how to retrofit your mysqli functions to work as mysql functions with older versions of PHP.

If you see:

$dbc = mysqli_connect(localhost, 'mork', 'fromork');
mysqli_select_db($dbc, 'alien_database');

you’ll use:

In general, you just remove the i from mysqli, making it mysql, and then ...