通过PHP访问MySQL.doc

原文: 
Getting PHP to Talk to MySQl
Now that you’fortable using the MySQL client tools to manipulate data in the database, you can begin using PHP to display and modify data from the database. PHP has standard functions for working with the , we’re going to discuss PHP’s built-in database functions. We’ll also show you how to use the The PHP Extension and Application Repository (PEAR) database
functions that provide the ability to use the same functions to access any supported database. This type of es from a process called abstraction. In programming interfaces, abstraction simplifies plex interaction. It works by
removing any nonessential parts of the interaction, allowing you to concentrate on the important parts. PEAR’s DB classes are one such database interface abstraction. The information you need to log into a database is reduced to the bare minimum. This standard format allows you to interact with MySQL, as well as other databases using the same functions. Similarly, other MySQL-specific functions are replaced with generic ones that know how to talk to many databases. For example, the MySQL-specific connect function is:
mysql_connect($db_host, $db_username, $db_password);
versus PEAR’s DB connect function:
$connection = DB::connect("mysql://$db_username:$db_password@$db_host/$db_database");
The same basic information is present in mands, but the PEAR function also specifies the type of databases to which to connect. You can connect to MySQL or other supported databases. We’ll discuss both connection methods in detail.
In this chapter, you’ll learn how to connect to a MySQL server fromPHP, how to use PHP to access and retrieve stored data, and how to correctly display information to the user.
1 The Process
The basic steps of performing a query, whether using the mand-line tool or PHP, are the same:
• Connect to the database.
• Select the database to use.
• Build a SELECT statement.
• Perform the query.
• Display the results.