Checking for duplicate records before update?

[Jas <jason.gerfen@xxxxxxxxxxxx>]

Problem. I have a database table that looks like this:
eg.
+------+----------+-------------------+---------------+---------+
| id   | hostname | mac               | ip            | vlan    |
+------+----------+-------------------+---------------+---------+
| 1014 | MTPC-01  | 00:02:B3:A2:9D:ED | 155.97.15.11  | Vlan-29 |
| 1015 | MTPC-02  | 00:02:B3:A2:B6:F4 | 155.97.15.12  | Vlan-29 |

This table will hold a very large number of entries, all unique.  I have 
created a simple HTML form which updates the entries but before it does 
it checks to see if records already exist that contain either the same 
IP value, the same MAC value or the same Hostname value.  If any of 
these items exist it currently discards the posted informaiton and 
prompts the user to re-enter because I cannot have duplicate entries of 
either the hostname, mac, ip fields.

Here is my function:
eg.
$x = mysql_query("SELECT * FROM $table WHERE hostname = 
'$_POST[hostname]' OR ip = '$_POST[ip]' OR mac = '$_POST[mac]' NOT id = 
'$_SESSION[id01]'")or die(mysql_error());
$num = mysql_num_rows($x);
  if($num == "0") {	
    unset($_SESSION['search']);
    require 'dbase.inc.php';
    $table = "hosts";
    $sql = @mysql_query("UPDATE $table SET hostname = 
\"$_POST[hostname]\", mac = \"$_POST[mac]\", ip = \"$_POST[ip]\", vlan = 
\"$_POST[vlan]\" WHERE id = \"$_SESSION[id01]\"")or die(mysql_error());
    echo "Form worked!";
} elseif ($num != 0) {
  unset($_SESSION['search']);
  echo "Form didn't work because 1 of the 3 fields were present in 
another record!!! Please try again.";
} else {
  echo "RTM again please!"; }

I think what I really need to know is if there is a quick way to sort 
through the results of the current database records and do comparisons 
against the form.  If any one has done something like this before could 
you please show me an example or point me to a good resource.  Thanks in 
advance.
Jas

--
PHP Database Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php