Question

If I’ve got a column in a database, I want to write a migration that generates another column that contains the md5 hash of the first column. The encryption I can do, but roughly what should the migration look like, structurally? Do I just do a for-each?

Answer 1

I would do it like this with a sql query because this is about the whole table and iteration would slow it down useless.

add_column :table_name, :password_md5, :string
ActiveRecord::Base.connection().execute("UPDATE table_name SET password_md5=MD5(password_plain)")