Ruby on Rails with external database, issues with web requests

I need to use Ruby on Rails with an external Postgres database. I have hooked up models to the database, and can run searches to the database using calls like Model.all. However, when I try and do a web request of the same data, I get the following error:

Started GET "/v1/products" for 127.0.0.1 at 2016-01-19 22:53:34 -0800

ActiveRecord::PendingMigrationError (

Migrations are pending. To resolve this issue, run:

    bin/rake db:migrate RAILS_ENV=development

):

I am an amateur Rails and database user, so I'm not sure what exactly a migrate does, but I do not have write permissions, so I cannot run one.

So, what can I do to the Rails project such that I can complete these web requests without needing to perform a migration? Any help is greatly appreciated!