Check if table and columns exist to use in Rails migrations
- #check for column
- ActiveRecord::Base.connection.tables.include?(name)
- #check for table
- Model.columns_hash.has_key("column_name")?
Rants About Rails Database Migrations
Migrations as version control for databases
When I first learned about Rails migration, I immediately thought that dropping down a revision would be something you would do often. In actuality, Rails migrations is more like a version control for databases. Since databases changes require modifications to both code and data, you cannot simply use a source code version control system like Subversion or Sourcesafe. You need a more advanced revisioning system for databases… hence Rails Migrations.