I am building a system, mostly for consolidating learning but will be used in practice. 
I will try and verbally explain the part of the E-R diagram I am focusing on:
Each cadet can have many uniformID's
Each Uniform ID is a new entry in table uniform, so cadets (table) may look like:
id | name    | ... | uniformID
1  | Example | ... | 1,2,3
uniform table:  
id | notes             | cadet
1  | Need new blahh    | 1
2  | Some stuff needed | 1
3  | Whatever you like | 1
On second thought, looks like I wont need that third column in the db.
I am trying to iterate through each id in uniformID, code:
<?php
$cadet = $_GET['id']; // set  from URL
$query = mysql_query("SELECT `uniformID` FROM `cadets` 
  WHERE id = '$cadet' LIMIT 1") 
  or die(mysql_error()); // get uniform needed as string
// store it
while ($row = mysql_fetch_array($query)) {
  $uniformArray = $row['uniformID']; 
}
echo $uniformArray . "  ";
$exploded = explode(",", $uniformArray); // convert into an array
// for each key in the array perform a new query
foreach ($exploded as $key => $value) {
  $query(count($exploded));
  $query[$key] = mysql_query("SELECT * FROM `uniform` WHERE `id` = '$value'");
}
?
As I say, this is mainly for consolidation purposes but I have come up with a error, sql is saying:
  Fatal error: Function name must be a string in C:\wamp\www\intranet\uniform.php on line 82
line 82 is:
$query[$key] = mysql_query("SELECT * FROM `uniform` WHERE `id` = '$value'");
I wasn't sure it would work so I tried it and now i'm stuck!
EDIT:
Thanks to everyone who has contributed to this! This is now the working code:
foreach ($exploded as $key => $value) {
              //$query(count($exploded));
              $query = mysql_query("SELECT * FROM `uniform` WHERE `id` = '$value'");
              while ($row = mysql_fetch_array($query)) {
                echo "<tr>
                  <td>" . $row['id'] . "</td>
                  <td>" . $row['note'] . "</td>
                </tr>";
              }
            }
Added the while and did the iteration by nesting it in the foreach