How to Manage Null Constraints With Migrations in Ruby on Rails

Ruby on Rails makes it easy to write migrations to modify your database schema. But null constraints... Tagged with ruby, rails, webdev.Ruby on Rails makes it easy to write migrations to modify your database schema.But null constraints are a topic that requires some special attention. If you don't handle null constraints properly, a poorly written migration can easily wreak havoc on your database and bring down your production server.What is a Null Constraint?By default most databases allow you to store NULL values in your table columns. Sometimes you might want to specify that a certain value has to exist, and you can apply a null constraint to enforce that.Then whenever a record attempts to save a NULL value, the database transaction will roll back nicely and prevent it from doing so.