Code returns:
Notice: Undefined offset: 0  line 60
Notice: Undefined offset: 1  line 61
Notice: Undefined offset: 2  line 62
I don't know where is a mistake. I have no idea, so I need some help.
Part of code is below:
    private function action($action, $table, $where = array()) {
        if(count($where) === 3) {
            $operators = array('=','>','<','>=' ,'<=');
            $field      = $where[0]; //-----> LINE 60
            $operator   = $where[1]; //-----> LINE 61
            $value      = $where[2]; //-----> LINE 62
            if(in_array($operator, $operators)) {
            $sql = "{$action} FROM {$table} WHERE {$field} {$operator} ?";
                if(!$this->query($sql, array($value))->error()) {
                    return $this;
                }
            }
        }
        return false;
    }
 
    