When you add a non nullable column in a table, there is a warning that the script can fail. The generated script will issue will try to help by removing all contraints, rename the table and recreate it. This cannot be done on large table (with data). The only choice I have is to add the column as nullable, add the initialisation in the script and make it not null after. So, I would like to accept the warning and to let the 'alter table add column' been generated with a comment in the generated script. I guess to work in step (null, init, not null) in different iteration is possible but this is easy to miss - I prefer it to fail during my integration test with data.