How to use the Active Record design pattern in PHP for data management and queries?

@dana 

The Active Record design pattern is a popular pattern used for data management and queries in object-oriented programming. In PHP, the Active Record pattern is commonly used in conjunction with database systems, such as MySQL or PostgreSQL.

To use the Active Record pattern in PHP, you can follow these general steps:

1. Create a class for each database table you want to work with. Each class should extend a base class that provides the basic database operations, such as querying, updating, and deleting records.

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class User extends ActiveRecord {
    protected static $table_name = 'users';
}

1. Define instance variables that correspond to the columns in the database table.

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class User extends ActiveRecord {
    protected static $table_name = 'users';
    public $id;
    public $username;
    public $password;
}

1. Define methods for CRUD operations on the database table.

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class User extends ActiveRecord {
    protected static $table_name = 'users';
    public $id;
    public $username;
    public $password;

    public static function find_by_id($id) {
        $result_array = static::find_by_sql("SELECT * FROM " . static::$table_name . " WHERE id={$id} LIMIT 1");
        return !empty($result_array) ? array_shift($result_array) : false;
    }

    public static function find_by_sql($sql) {
        $result_set = self::$database->query($sql);
        $object_array = array();
        while ($row = $result_set->fetch_assoc()) {
            $object_array[] = static::instantiate($row);
        }
        return $object_array;
    }
}

1. Instantiate objects of the class to interact with the database table.

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$user = User::find_by_id(1);

This is just a basic example of how to use the Active Record pattern in PHP. You can customize your implementation to fit your specific needs and use cases. Additionally, there are many libraries and frameworks that provide Active Record implementations in PHP, such as Laravel's Eloquent ORM and Yii's Active Record.