The main reason I'm asking is because I'm supporting an inherited application that contains some poor desing structure. The primary key is a concatination of 3 numeric fields. I want to over time convert it to a single integer key.

Instead of manually adding new fields, I do it programmatically against my development, test and then eventually production databases. That minimizes my typos.

However, when I do it programmatically, the new fields are added to the end if the record row using alter table command.