The big challenge you have here is that you have two tables each with an identity primary key and foreign keys. You are going to have to do quite a bit of work to pull this off. Probably the approach I would take is to add a new column in the table you want to combine from. This new table needs to have a new int column that will become the key when the data moves. Update that column to have some values that don't exist in the current table. Then you will need to find and update all the associated rows in the other tables so the linkage will remain intact (but using the new column). Then insert your data to the other table using the newly created column as your value for the primary key in the new destination.