Mysql INSERT ... ON DUPLICATE KEY UPDATE响应

Question

Hello I have a table A and I want when a new value (not UPDATE) is inserted in that table to do an INSERT in table B, I tried to play with the responce of the $query INSERT INTO .. ON DUPLICATE KEY UPDATE but no luck, it always returns 1.

$query = "INSERT INTO table ".$fields." VALUES ".$values." ON DUPLICATE KEY UPDATE updated=1"
$response = $dbc->query($query);
if($response == 1)

I have also tried a 'hack' lets say, putting the UPDATE above the INSERT so if the entry doesnt exist to fail but that again returns 1 everytime.

 $query = "UPDATE table SET updated=1 ..;
 $response = $dbc->query($query);
 if($response == 1)

Answer 1

Thanks @boomoto for helping me figuring out the answer:

 $query = "UPDATE tableA ..
 $response = $dbc->query($query);
 if(mysqli_affected_rows($dbc)==0){
        $query2 = "INSERT INTO tableB ..
        $response2 = $dbc->query($query2);

        $query = "INSERT INTO tableA ..
        $response = $dbc->query($query);
    }   
 }