Learning PHP, MySQL & JavaScript, 6th Edition

Chapter 11. 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 in to 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.

The Process

The process of using MySQL with PHP is as follows:

1. Connect to MySQL and select the database to use.

2. Prepare a query string.

3. Perform the query.

4. Retrieve the results and output them to a web page.

5. Repeat steps 2 to 4 until all desired data has been retrieved.

6. Disconnect from MySQL.

We’ll work through these steps in turn, but first it’s important to set up your login details in a secure manner so people snooping around on your system have trouble getting access to your database.

Creating a Login File

Most websites developed with PHP contain multiple program files that ...