Running migrations for existing postgres table

[massimo]

You can take a look a this comment from Jose Valim

Phoenix 1.3 and Ecto with an existing database

You can just skip the migration. There is also a flag you can pass to the generator so it is not even generated in the first place. Also take a look at the mix ecto.load and mix ecto.dump tasks so you can dump the structure of the production database so you have something to develop/test against.