How can I update the sqlite db?

I'm new at Xcode. What im trying to do is to create a db on a view controller and fill a part of it in this view controller and the other part on an other view controller. Heres an example of what i want to do: I create a db with the columns "Name" and "lastname", I want to enter the name on the first view controller and the last name on an other view controller, but I want them to be on the same line or id. I already created the db and inserted the first part of the info but i don't know how to insert the other part of the db on the other view controller so that they appear on the same line. Can someone show me how to do it?