Everyday Rails

Simple data transfer with YamlDB

By Aaron Sumner, December 23, 2014. File under: .

I’ve got a very small side project going. So far, it’s only been for my benefit–but last night I decided I’d like to go ahead and deploy it at some point soon, so I’d need to switch out the simple SQLite database with something more robust. I also had test data I wanted to migrate over, though. What was the simplest way to get data out of my preliminary SQLite database and into something I could eventually move up to my production server?

Luckily, I’m not the first Ruby developer to run into this problem. And, there’s already a nice Ruby library to handle this use case. Within a few minutes, I’d found YamlDB, exported my initial dataset, and restored it into a new database.

I’d write up the process, but to be honest, there’s not much to write. The YamlDB README pretty much covers the whole procedure. In my case:

  1. I added yaml_db to my Gemfile.
  2. I ran the db:data:dump Rake task.
  3. I replaced sqlite3 with my production database adapter (in this case, mysql2), and updated my database.yml file as needed.
  4. I ran rake db:create to create my new development database.
  5. I ran rake db:migrate to build out my new database and update the schema for a different ORM.
  6. I ran the db:data:load Rake task to copy the exported data into the new database.
  7. I removed yaml_db from my Gemfile, ran bundle check to clean up Gemfile.lock, and committed the changes (omitting the data.yml file created by the process).

The whole process took less than five minutes. Now, this project is admittedly simple, with just a few data models and a couple thousand records at this point. I’ll try it again in the future when I need to migrate a larger dataset, but in the meantime I was pleased enough with my initial results that I wanted to pass it along.


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