Why would a schema-less database need migrations? Simple: to help you keep old data fresh as you change your data format. Recently added new columns to your MongoMapper model and need to update old values in your MongoDB collection? Terry Heath gives you Mongrations:
script/generate mongration update_followers_count_for_existing
You’ll get a new file with the familiar Rails migration format:
class UpdateFollowersCountForExisting < MongoMapper::Mongration def self.up end def self.down end end
Just add your own code to manipulate your data and call
rake db:mongrate. Mongrations include rake tasks for
Have comments? Send a tweet to @TheChangelog on Twitter.
Subscribe to The Changelog Weekly – our weekly email covering everything that hits our open source radar.