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

Depends on what SQL implementation you are using. Both MySQL and SQLite, for example, have ways to get last insert id. In fact, if you're using PHP, there's even a nifty function for exactly that mysql_insert_id().

You should probably look to use this MySQL feature instead of looking at all the rows just to get the biggest insert ID. If your table gets big, that could become very inefficient.