Can i use if condition on laravel database query?

Can i use if condition inside query, I want to use filter when $request->review = 7 it will show 7 days data and else condition default 30 days data .

$reviews = Review::orderBy('created_at', 'DESC')
    ->orWhere('created_at', '>=', if($request->review == "7"){ $month = 7 })
    ->where('listing_id', $id)
    ->where('user_id', Auth::User()->id)
    ->paginate(6, ['*'], 'review');

via Chebli Mohamed