Learning PHP, MySQL, JavaScript, CSS & HTML5, 3rd Edition

Chapter 10. Accessing MySQL Using PHP

If you worked through the previous chapters, you’re proficient in using both MySQL and PHP. In this chapter, you will learn how to integrate the two by using PHP’s built-in functions to access MySQL.

Querying a MySQL Database with PHP

The reason for using PHP as an interface to MySQL is to format the results of SQL queries in a form visible in a web page. As long as you can log into your MySQL installation using your username and password, you can also do so from PHP. However, instead of using MySQL’s command line to enter instructions and view output, you will create query strings that are passed to MySQL. When MySQL returns its response, it will come as a data structure that PHP can recognize instead of the formatted output you see when you work on the command line. Further PHP commands can retrieve the data and format it for the web page.

Note

To get you started, in this chapter I use the standard, procedural mysql function calls, so that you’ll be up and running quickly, and able to maintain older PHP code. However, the new object-oriented mysqli functions (the i stands for improved) are becoming the recommended way to interface with MySQL from PHP, so in the following chapter I’ll show you how to use these too (or instead, because the old functions have become deprecated and could be removed from PHP at some point).

The Process

The process of using MySQL with PHP is:

1. Connect to MySQL.

2. Select the database to use.

3. Build a query string.

4. Perform the ...