Creating Active Record Classes

We need to create two Active Record classes, UserRecord and PostRecord, to represent data records in the users and posts tables, respectively. Active Record classes must extend from the base class ActiveRecord, and their properties must match exactly to the fields of the corresponding tables.

To better organize our directories, we create a new directory protected/database to hold the class files. We also modify our application configuration by inserting the following lines. It is equivalent to adding the directory protected/database to PHP include_path, which allows us to use the classes without explicitly including them.

Instead of writing the classes manually, we will use the PRADO command line tool again to generate the classes for us.

Under the blog directory, run the following command to enter into the interactive mode of the command line tool:

php path/to/prado-cli.php shell .

We should see

Command line tools for Prado 3.1.0. ** Loaded PRADO appplication in directory "protected". PHP-Shell - Version 0.3.1 (c) 2006, Jan Kneschke >> use '?' to open the inline help >>

At the prompt, enter the following two commands to create UserRecord and PostRecord classes:

>> generate users Application.database.UserRecord >> generate posts Application.database.PostRecord

Here we used the namespace format again to specify the classes to be created. The path Application.database.UserRecord indicates that we want the UserRecord class file to be protected/database/UserRecord.php.

We should see the following directory structure with two new files under protected/database:

If we check the PostRecord class file, we should see the following content.

class PostRecord extends TActiveRecord { const TABLE='posts'; public $post_id; public $author; public $create_time; public $title; public $content; public static function finder($className=__CLASS__) { return parent::finder($className); } }

As we see, for each field in the posts table, the class has a corresponding data member. The constant TABLE specifies the table name for the PostRecord. The static method finder() allows us to perform query and retrieve post data in terms of PostRecord objects.

We can use the command line tool to do some testing with our newly created Active Record classes. Still in the interactive mode of the command line tool, we enter a PHP statement and should see the following. Interested readers may try some other PHP statements, such as UserRecord::finder()->findAll().

>> PostRecord::finder()->findAll() array ( [0] => PostRecord#1 ( [post_id] => '1' [author] => 'admin' [create_time] => '1175708482' [title] => 'first post' [content] => 'this is my first post' [TActiveRecord:_readOnly] => false [TActiveRecord:_connection] => null [TComponent:_e] => array() ) )