Ruby on Rails: How do I add a not null constraint to an existing column using a migration?
In my Rails (3.2) app, I have a bunch of tables in my database but I forgot to add a few not null constraints. How can I write a migration which adds not null to an existing column?
Solution 1:
You can also use change_column_null:
change_column_null :table_name, :column_name, false
Solution 2:
For Rails 4+, nates' answer (using change_column_null) is better.
Pre-Rails 4, try change_column.