card/lib/generators/migration/USAGE
Description:
Generates a migration of database schema or content.
Example:
<%= banner_command %> generate migration better_comments -m mymod
This will create:
mod/mymod/data/transform/(migration_number)_better_comments.rb
<%= banner_command %> generate migration better_comments -m mymod --schema
This will create:
mod/mymod/data/schema/(migration_number)_better_comments.rb