protected function _addSimpleCondition($type, $column_name, $separator, $value)
        {
            $multiple = Arrays::is($column_name) ? $column_name : array($column_name => $value);
            $result = $this;

            foreach($multiple as $key => $val) {
                // Add the table name in case of ambiguous columns
                if (count($result->_join_sources) > 0 && strpos($key, '.') === false) {
                    $table = $result->_table_name;

                    if (!is_null($result->_table_alias)) {
                        $table = $result->_table_alias;
                    }

                    $key = "{$table}.{$key}";
                }

                $key = $result->_quoteIdentifier($key);
                $result = $result->_addCondition($type, "{$key} {$separator} ?", $val);
            }

            return $result;
        }