    public function getQueryGroupby()
    {
        $R1 = 'R1_' . $this->field->id;
        $R2 = 'R2_' . $this->field->id;
        return "$R2.id";
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.