Adding a column before another one in Rails

Question

I'm looking to put a column at the front of my table I know you can do

add_column :customer, :first_name, after: :last_name

but is there a way to do :before?

Answer 1

You're able to insert a column at the front of your table by using the :first option:

add_column :table_name, :column_name, :column_type, first: true

You can still use :after to handle all other positioning cases.

Answer 2

These are mysql-specific options by the way.

https://github.com/rails/rails/blob/80e66cc/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb#L50-L55 lists the available options, looks like they only support before and first.

For what it's worth, PostgreSQL only supports adding columns to the end of the table.

Related question: alter table add ... before `code`?