Calculating costs from database

[radagast]

• Hello
   
  Please can someone PLEASE PLEASE help me.
   
  I have a form that the user inputs dimension and weights of a parcel. They then request a price on request I do the following:
   
  $volume_mass = 50(dimm1) *50 (dimm2) * 50 (dimm3);
  so that means $volume_mass = 125000
  I then take the total of the weight - $actual_mass = 20(weight)
   
  I am doing the following query to see what service are available
   
    $data = "SELECT * FROM rates WHERE hub_from = 'nxd' AND hub_to = 'auk'";
    $result = mysql_query($data)
    or die ("Error in query: $data. " . mysql_error());
   
  if (mysql_num_rows($result) > 0)
  {
   
  while($row = mysql_fetch_object($result))
   
     
                               
      } 
                ?>
   
  So I get multiple results and I need to now work out the cost per result.
   
  Example of results from rates table
   
  $service $volume $base $min_kg $per_kg
  AIR       5000       70.00   5             4
  ECO       4000       80.00   10     4
  LOX       5000       45.00     1             35
  LSE       5000       45.00     1             35
  OVN       5000       70.00     10     4
   
  Know I need to do the following per result (per service)
   
  

1. 
   
2. need to the volume factor from the service -  &totalv = $volume_mass / $volume (from the rates table)
   
3. Check if which is now greater between $actual_mass and $totalv - $charge_mass = $actual_mass <> $totalv
   
4. then need to calculate the costs - if $charge_mass <= $min_kg then $total_cost = $base echo "$total_cost" else if $charge_mass > $min_kg then $total_cost = ($charge_mass - $min_kg) *$per_kg + $base  echo "$total_cost"

[*]

 

   

 

Any help would be greatly appreciated

 

[Psycho]

It doesn't look like you need an if/else. You can simply calculate the price based upon the base plus the "overage" times the rate. the overage being the amount of the $charge_mass over the minimum. If the $charge_mass is less than the minimum, the overage would be 0.

 

Here is the verbose solution:

$data = "SELECT *, ($volume_mass/`volume`) as totalv
         FROM rates
         WHERE hub_from = 'nxd'
           AND hub_to = 'auk'";
  $result = mysql_query($data)
  or die ("Error in query: $data. " . mysql_error());

while($row = mysql_fetch_object($result))
{   
    $charge_mass = max($actual_mass, $row['totalv']);
    $overage = max($charge_mass - $row['min_kg'], 0);
    $total_cost = $row['base'] + ($overage * $row['per_kg']);
    echo "{$row['service']}: {$total_cost}<br>\n";
} 

 

Or you can make it more compact as follows (use the query from above):

while($row = mysql_fetch_object($result))
{   
    $total_cost = $row['base'] + (max(max($actual_mass, $row['totalv']) - $row['min_kg'], 0) * $row['per_kg']);
    echo "{$row['service']}: {$total_cost}<br>\n";
} 

 

Personally, I'd go with the verbose code with comments

[radagast]

Hi mjdamato

 

Sorry for taking so long to reply. BUT thanks alot this worked like a CHARM..

 

You ROCK!!