'SQLSTATE [HY000]：将数据插入数据库的常规错误？

Question

所以我正在创建一个使用php类将数据插入数据库的登录系统。以下是数据库的插入方法。

public function insert($table, $fields = array()){
        if(count($fields)){
            $keys   = array_keys($fields);
            $values = '';
            $x      = 1;
            foreach($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;
    }

下一个方法是我抓住输入字段输入数据库。

public function create($fields = array()) {
      if ($this->_db->insert('users', $fields)) {
        throw new Exception('There was a problem with creating an account. Try again later.');
      }
    }

这就是我注册用户的方式。

  if ($validation->passed()) {
        //register user
        $user = new User();

        try {

          $salt = Hash::salt(32);

          $address =
            Input::get('street_address') . ':' .
            Input::get('city') . ':' .
            Input::get('state_province') . ':' .
            Input::get('zip_code')
          ;

          echo $address;

          $user->create(array(
            'first_name' => Input::get('first_name'),
            'last_name' => Input::get('last_name'),
            'email' => Input::get('email'),
            'address' => $address,
            'password' => Hash::make(Input::get('password'), $salt),
            'salt' => $salt,
            'date_joined' => date('Y-m-d H:i:s'),
            'groups' => 1
          ));


          Session::flash('home', 'You have been registered and can now log in!');
          header('Location: index.php');


        } catch(Exception $e) {
          die($e->getMessage());
        }

        // Session::flash('success', 'You registered successfully!');
        // header('Location: index.php');

      } else {
        //show errors
        foreach($validation->errors() as $error) {
          echo $error . "<br>";
        }
      }

我尝试修复查询并确保没有错误，但我似乎无法找到任何错误。