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9 years ago
You can access MySQL tables in an objective way. Suppose you have a table named Users that has fields: UserID, UserName, UserPassword, UserBirthday, you can create a PHP class extending DataObject that is associated with this table:
<?php 
class User extends DataObject {
    // name: Table Name, key: Primary Key (can be an array), auto: AUTO_INCREMENT field
    protected static $_table = array('name' => 'Users', 'key' => 'UserID', 'auto' => 'UserID');
    // relationships between PHP properties and MySQL field names
    protected static $_propertyList = array('id' => 'UserID', 'name' => 'UserName', 'password' => 'UserPassword', 'birthday' => 'UserBirthday');
    
    // A method that fetches all users as an array
    public static function GetAll() {
        global $dbh;
        $sql = 'SELECT * FROM Users';
        $stmt = $dbh->query($sql);
        $users = array();
        while ($user = $stmt->fetchObject(__CLASS__)) {
            $users[] = $user;
        }
        return $users;
    }
    // Methods that fetch a specific user
    public static function GetUserByName($name) {}
    public static function GetUserByID($name) {}
    
    // Methods for the current user object
    public function checkPassword($password) {return $this->password == $password;}
    public function showLink() {return "<a href=\"user.php?i={$this->id}\">{$this->name}</a>";}
}

// Then, you can create an instance of this class to insert a row in your table
$user = new User();
$user->name = 'oct1158';
$user->password = '789012';
$user->useFunction('birthday', 'NOW()');
echo 'Field birthday uses MySQL Function: ', $user->birthday, '<br>';
if ($user->insert()) {
    echo 'New User ID: ', $user->id, '<br>';
    
    // Update the row
    $user->password = '112233';
    $user->update();
} else {
    echo 'INSERT Failed<br>';
}
// Get a specific user by a query
$sql = 'SELECT * FROM Users WHERE UserName = ?';
$stmt = $dbh->prepare($sql);
$stmt->execute(array('admin'));
$admin_user = $stmt->fetchObject('User');
echo 'Admin ID is ', $admin_user->id, '.<br>';
echo 'Admin Birthday is ', $admin_user->birthday, '.<br>';

// Get all users by a static method of that class
$users = User::GetAll();
echo '<br>';
echo $users[0]->name, ', ', $users[0]->birthday, '<br>';
echo $users[1]->name, ', ', $users[1]->birthday, '<br>';
echo $users[2]->name, ', ', $users[2]->birthday, '<br>';
echo '<br>';

// Create an empty user and then delete it immediately
$user = new User();
$user->insert();
$user->delete();
?>
The DataObject class example:
<?php 
class DataObject {
    private $changedFields = array(); // list of updated fields
    private $data = array(); // original row from PDOStatement
    private $funcFields = array(); // fields that use MySQL functions
    // The properties above are private in this class, so even if in your subclass you define some properties named the same, or you associate a property of the same name with a field in your table, they will never influence these properties.
    function __get($property) {
        if (isset($this::$_propertyList[$property])) {
            return $this->data[$this::$_propertyList[$property]]; // access fields by PHP properties
        } else {
            return $this->$property; // throw the default PHP error
        }
    }
    function __set($property, $value) {
        if (isset($this::$_propertyList[$property])) {
            $field = $this::$_propertyList[$property];
            $this->data[$field] = $value; // update $data
            
            // take down changed fields
            if (!in_array($field, $this->changedFields)) {
                array_push($this->changedFields, $field);
            }
            $index = array_search($field, $this->funcFields);
            if ($index !== false) {
                unset($this->funcFields[$index]);
                $this->funcFields = array_values($this->funcFields);
            }
        } else {
            // For fetchObject
            $this->data[$property] = $value; // redirect to Array $data
        }
    }
    private function checkPrimaryKey() {}
    private function clear() {}
    public function delete() {}
    public function insert() {}
    public function update() {}
    public function useFunction($property, $function) {}
}
?>
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