Khoerodin Developer, writer, and maker |

Developer, writer, and maker

Don't Use Rails Schema! Use This Instead

There are two things to note about schema.rb

  • It is a reflection of the database structure in Ruby.
  • It is database-agnostic. This means that no matter what database you use, the syntax and structure will be largely the same.
  • Advanced database features are not covered.

schama.rb will be very useful when we are faced with a scenario:

  • Our application has thousands of migration files. This causes a lot of wasted time because it takes a long time to set up a new environment.
  • The migration files may contain code that is only compatible with the old version of the database. Therefore, it will fail when executed.

Running rails db:setup is the quickest solution to both (or more) of these problems. This command will build the database from schema.rb.

But what if the database has complex logic that is not captured in schema.rb? The solution is to use structure.sql

Advantages of structure.sql

The advantage of using structure.sql is that it will copy the structure of the database exactly, including functions, views, constraints, stored procedures, etc., which is not possible with schema.rb.

Switch from schema.rb to structure.sql

Open the config/application.rb file

module YourApp
  class Application < Rails::Application
    config.load_defaults x.x

    # Add this line:
    config.active_record.schema_format = :sql

Then run rails db:migrate and the file db/structure.sql will be generated. When we run the rails db:setup command it no longer uses schema.rb but uses structure.sql.