Mysqli查询结果返回空，但不应该

Question

I run the query directly through PHP MyAdmin and it returns 1 result. Am I missing something? Well clearly I must be and I can't wrap my head round it!?!

I think I'm just tired or something! Any help would be much appreciated:-

$query_road_tax = mysqli_query($conn011, "SELECT * FROM road_tax_pricing WHERE (tax_from_co2 <='$vehicle_co2' AND tax_upto_co2 >='$vehicle_co2'");
$row_road_tax = mysqli_fetch_assoc($query_road_tax);
$Six_Month=$row_road_tax['tax_6month'];
$Twelve_Month=$row_road_tax['tax_12month'];

Answer 1

Closing ) and " issue it would be

$query_road_tax = mysqli_query($conn011, "SELECT * FROM 
road_tax_pricing WHERE (tax_from_co2 <='$vehicle_co2' AND tax_upto_co2 >='$vehicle_co2')");