Learning PHP & MySQL, 2nd Edition

Chapter 13. Modifying MySQL Objects and PHP Data

In Chapter 12 you learned about the advantages of XHTML over traditional HTML. This chapter explores using all of the concepts you’ve learned together so far to perform more complicated database tasks with PHP. You’ll learn how to create and modify both MySQL data and database objects from within PHP. We’ll go over dynamically creating HTML hyperlinks to allow your end user to expand or modify data from a database query. In fact, after you learn about sessions in the next chapter, you’ll have everything you need to create full-fledged applications.

Changing Database Objects from PHP

The SQL query string remains the common tool for giving database commands. You can just as easily create and modify database objects with standard SQL that is called the same way you execute queries. Sometimes you’ll want to create database objects from within PHP. We’ll begin with creating a table, which is an example of creating objects.

Creating a Table

We’ve previously created the books and authors tables, but we haven’t created the purchases table. We’ll create one using the PHP shown in Example 13-1.

Example 13-1. Creating a table from a PHP page in create_table.php

<?php
include('db_login.php');
require_once( 'DB.php' );
    $connection = DB::connect( "mysql://$db_username:$db_password@$db_host/
$db_database");
if (!$connection)
{
    die ("Could not connect to the database: <br>". DB::errorMessage(  ));
};
$query = 'CREATE TABLE purchases ( purchase_id int(11) ...