Whats wrong with this query?

[sixlead]

$query2Count = 0;
$query = "SELECT id, fname, lname FROM contacts ORDER BY lname ASC";
$results = mysql_query ($query) or die(mysql_error());
while( $row = mysql_fetch_array ( $results )){
$contactId = $row['id'];
$contactFname = $row['fname'];
$contactLname = $row['lname'];
$query2 = "SELECT groupID FROM contactgroups WHERE contactID = $contactId";
$results2 = mysql_query ($query2) or die(mysql_error());
while( $rows = mysql_fetch_array($results2)){
if (mysql_num_rows($results2) == 0){
$query2Count = $query2Count + 1;
echo $contactId;
echo " - ";
echo $contactFname;
echo " - ";
echo $contactLname;
echo "<br>";
}
}
}
echo "Total matches for secondary query is :";
echo $query2Count;

I am trying to find ids from the first table that are not present in the second table of which there at least 4000 yet nothing is found.

Any help would be appreciated.

[Roger_Ramjet]

I have not bothered to examine your code as the answer to your problem is 1 query with a LEFT JOIN . Read the manual and it will tell you how to find all ids with no match in the second table.

[sixlead]

Fantastic, thank you the link to the manual is what I really needed. Problem solved and thanks for the tip.