Newbie question on adding columns and references to existing table

I took a run at the blog tutorial and now I am working on my first
Ruby app. I have two models with the same relationship as the post /
comments example in the blog tutorial.

When I created the second model I forgot to add the 'reference' column
to link the two together.

I can't seem to find anywhere the correct way to fix this and in
general to add columns to an existing database table.



Migrations. Look into migrations. You can add, remove, change, etc.
columns and anything in the database through migrations.