[FIXED] How to change a nullable column to not nullable in a Rails migration?

Issue

I created a date column in a previous migration and set it to be nullable. Now I want to change it to be not nullable. How do I go about doing this assuming there are null rows in that database? I'm ok with setting those columns to Time.now if they're currently null.

Solution

If you do it in a migration then you could probably do it like this:

# Make sure no null value exist
MyModel.where(date_column: nil).update_all(date_column: Time.now)

# Change the column to not allow null
change_column :my_models, :date_column, :datetime, null: false

Answered By - DanneManne

Answer Checked By - Senaida (PHPFixing Volunteer)