SQL - How to find the highest number in a column?

Question

Let\'s say I have the following data in the Customers table: (nothing more)

ID   FirstName   LastName
-------------------------------
20   John        Macken         


        

Answer 1

In PHP:

$sql = mysql_query("select id from customers order by id desc");
$rs = mysql_fetch_array($sql);
if ( !$rs ) { $newid = 1; } else { $newid = $rs[newid]+1; }

thus $newid = 23 if last record in column id was 22.