Question

Assume I have the following result set from a mysql DB call (basic example, main will have much more data):

customerID   |   name     |     item     |     price
====================================================
11111        |   John     |    pizza     |   10.00
11111        |   John     |    burger    |   5.00
11111        |   John     |    drink     |   2.00
22222        |   Mike     |    lasagna   |   11.00
22222        |   Mike     |    drink     |   2.00
33333        |   Sam      |    burger    |   5.00
33333        |   Sam      |    fries     |   3.00
33333        |   Sam      |    shake     |   5.00
33333        |   Sam      |    drink     |   2.00

I want to display the results in a tabular form but limit the times customerID and name appear, as well as show a subtotal by each customer:

customerID   |    name    |   item    |    price
===================================================
11111        |    John    |  pizza    |   10.00
             |            |  burger   |   5.00
             |            |  drink    |   2.00
             |            |           |   **17.00**
             |            |           |
22222        |    Mike    |  lasagna  |   11.00
             |            |  drink    |   2.00
             |            |           |   **13.00**
             |            |           |
33333        |    Sam     |  burger   |   5.00
             |            |  fries    |   3.00
             |            |  shake    |   5.00
             |            |  drink    |   2.00
             |            |           |   **15.00**

I know I could make multiple DB calls but this is wasteful when it can be done in one. I am having problems cycling through my result set in table 1 and properly formatting with PHP using as shown in table 2. Is it possible the way I have it shown or do I have to make multiple DB calls to do so?

Answer 1

This is better solved directly in PHP, because you will be free to modify the output as you wish.

So basically you will do something like (untested):

$res = mysql_query("SELECT costumerID, name, item, price
                    FROM orders 
                    ORDER BY customerID, item");

echo "<table id='orders'>".
      "<tr><th>Name</th>".
      "<th>Item</th>".
      "<th>Price</th></tr>";

$lastCostumer = -1;
$subTotal = 0; 
while ($row = mysql_fetch_array($res))
     {
     // New costumer
     if ($lastCostumer != $row['costumerID'])
           {
           // Write the subtotal of previous costumer, unless this is the 1st one
           if ($lastCostumer != -1)
              echo "<tr><td></td>".
                   "<td></td>".
                   "<td><b>**".$subTotal."**</b></td></tr>";

           $subTotal = 0; 
           echo "<tr><td>".$row['name']."</td>".
                "<td>".$row['item']."</td>".
                "<td>".$row['price']."</td></tr>";

           $subTotal = $subTotal + $row['price'];
           $lastCostumer = $row['costumerID'];
           }
     else // Same costumer
           {
           echo "<tr><td></td>".  // Don't write the name
                "<td>".$row['item']."</td>".
                "<td>".$row['price']."</td></tr>";

           $subTotal = $subTotal + $row['price'];
           }
     }

// Write the subtotal of last costumer
echo "<tr><td></td>".
     "<td></td>".
     "<td><b>**".$subTotal."**</b></td></tr>";

echo "</table>";