Rails Spree project - Database inaccessible from other contributor on Git

Question

Ι have started a Rails Spree project along with a friend, and we use GitHub for version control.

I have created the sample project in my machine, and installed Spree functionality on it. This creates a database with sample products, like so:

When my friend clones the project in his machine and imports it, running rails server fails with MigrationException and asks him to run rake db:migrate.

Running rake db:migrate fails after a few migrations, on nonexisting db column.

rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

SQLite3::SQLException: no such column: spree_calculators.deleted_at: SELECT  "spree_calculators".* FROM "spree_calculators" WHERE "spree_calculators"."deleted_at" IS NULL  ORDER BY "spree_calculators"."id" ASC LIMIT 1000C:in `find_each'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:15:in `migrate_preferences'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:4:in `up'
C:in `migrate'
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: spree_calculators.deleted_at: SELECT  "spree_calculators".* FROM "spree_calculators" WHERE "spree_calculators"."deleted_at" IS NULL  ORDER BY "spree_calculators"."id" ASC LIMIT 1000
C:in `find_each'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:15:in `migrate_preferences'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:4:in `up'
C:in `migrate'
SQLite3::SQLException: no such column: spree_calculators.deleted_at
C:in `find_each'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:15:in `migrate_preferences'
C:/Users/User/xylino/xylino_serena/db/migrate/20151011115236_migrate_old_preferences.spree.rb:4:in `up'
C:in `migrate'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

After that, running rails server again is succesful, but no products or other items can be seen in his sample page, like so:

There has to be something wrong with the database. Parts or all of it are inaccessible, possibly due to security issues because we're sharing the db, but I cannot find a solution. Or maybe it's just a botched migration problem

Any ideas?

Answer 1

Rails migrations can sometimes get out-of-date with your live environment. This can happen if you have a separate database team that updates your production environment and forgets to make a migration for it. It can also happen if you update your migrations, forget to re-run them, or somehow get in an inconsistent state.

The best way to do this, is for a new developer on a project to run rake db:schema:load. This will load the database structure from your db/schema.rb file, which will have everything as up-to-date as possible. Afterwards, you can run rake db:migrate just to verify everything is migrated.

However, after that, you will have the structure of the database, but not the content of the database. So say you have a users table with dimitris@example.com as a user. Your colleague will have a users table with no users in it.

To fix that, you can edit the db/seeds.rb file. In there, you can do stuff like:

User.create(name: 'Dimitris Sfounis', email: 'dimitris@example.com', password: 'password123')
User.create(name: 'Some Colleague', email: 'colleague@example.com', password: 'password123')
Product.create(name: 'Ruby on Rails Tote', price: 15.99)
Product.create(name: 'Ruby on Rails Bag', price: 22.99)

The idea here is that you create demo data, enough to get up and running and testing stuff in a brand new and empty database. With that in place, rake db:seed will provide enough data to run the app.

If that is not good enough, and you want exact copies of the database for all the developers, you could upload your SQLite database and have each of them download a new copy when they pull the database down. However, this is tough to manage, because each time someone updates the master branch with a new migration, you'll need to update the SQLite file. For other databases, you can dump and restore with pg_dump (Postgres) or mysqldump (MySQL).