so when you say you have a column, I assume that you are presenting the data in an HTML Table element? I dont see this as a PHP or SQL issue/question.
otherwise if you are going to try to sort the data server side, you would have to have to initiate a postback, send PHP some value that it knows what columun to sort, then requery SQL to generate a new table based on that column sort. I dont think this would be a good approach.
Again, try to handle this client side.