Add column with default null value

Question

I use rails with postgreSQL, I want to add a new column with a default null value, do I have to specify the default null value?

add_column :posts, :string, default: null 

Answer 1

You don't need to specify it. When you add new column to table without default value all the values will be null. Also: note that in ruby the equivalent of psql Null value is nil.