如何用OOP创建迷你cms？

Question

我正在使用OOP和im new。我只是不明白...我尝试了一切，我只是无法进行简单的文本编辑，例如：

我想制作一个表格，我可以在主页面上编辑文字。所以对于ex我想编辑页脚文本“bla bla版权”我想用简单的形式编辑它。听起来很容易，但对于我而言，它不是那么多。

这是我的注册/登录系统的示例，我试图使其与此类似，但无法弄明白。

class DB{
private static $_instance = null;
private $_pdo,
        $_query,
        $_error = false,
        $_results,
        $_count = 0;

private function __construct(){
    try{
        $this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') . ';dbname=' . Config::get('mysql/db'), Config::get('mysql/username'), Config::get('mysql/password'));
    } catch(PDOException $e){
        die($e->getMessage());
    }
}

public static function getInstance(){
    if(!isset(self::$_instance)){
        self::$_instance = new DB();
    }
    return self::$_instance;
}

public function query($sql, $params = array()){
    $this->_error = false;
    if($this->_query = $this->_pdo->prepare($sql)){
        $x = 1;
        if(count($params)){
            foreach($params as $param){
                $this->_query->bindValue($x, $param);
                $x++;
            }
        }

        if($this->_query->execute()){
            $this->_results = $this->_query->fetchAll(PDO::FETCH_OBJ);
            $this->_count = $this->_query->rowCount();
        } else {
            $this->_error = true;
        }
    }

    return $this;
}

public function action($action, $table, $where = array()){
    if(count($where) === 3){
        $operators = array('=', '>', '<', '>=', '<=');

        $field      = $where[0];
        $operator   = $where[1];
        $value      = $where[2];

        if(in_array($operator, $operators)){
            $sql = "{$action} FROM {$table} WHERE {$field} {$operator} ?";

            if(!$this->query($sql, array($value))->error()){
                return $this;
            }
        }
    }
    return false;
}

public function get($table, $where){
    return $this->action('SELECT *', $table, $where);
}

public function delete($table, $where){
    return $this->action('DELETE', $table, $where);
}

public function insert($table, $fields = array()){
    $keys = array_keys($fields);
    $values = null;
    $x = 1;

    foreach($fields as $field){
        $values .= '?';
        if($x < count($fields)){
            $values .= ', ';
        }
        $x++;
    }

    $sql = "INSERT INTO {$table} (`" . implode('`, `', $keys) . "`) VALUES ({$values})";

    if(!$this->query($sql, $fields)->error()){
        return true;
    }

    return false;
}

public function update($table, $id, $fields){
    $set = '';
    $x = 1;

    foreach($fields as $name => $value){
        $set .= "{$name} = ?";
        if($x < count($fields)){
            $set .= ', ';
        }
        $x++;
    }

    $sql = "UPDATE {$table} SET {$set} WHERE id = {$id}";

    if(!$this->query($sql, $fields)->error()){
        return true;
    }

    return false;
}

public function results(){
    return $this->_results;
}

public function first(){
    return $this->results()[0];
}

public function error(){
    return $this->_error;
}

public function count(){
    return $this->_count;
}

}