Rails : Create a drop table cascade migration

You could always run raw SQL in the migration.

MYSQL:

execute "DROP TABLE #{:table_name} CASCADE CONSTRAINTS PURGE"

PostgreSQL:

execute "DROP TABLE #{:table_name} CASCADE"

You can check the documentation of the built-in method drop_table here.

In Rails 4 you can do the following:

drop_table :accounts, force: :cascade

Put a file in your initializers directory called postgres.rb then did. This works for rails 4.1 anyway.

module ActiveRecord
    module ConnectionAdapters # :nodoc:
        module SchemaStatements
            def drop_table(table_name, options = {})
                execute "DROP TABLE  #{quote_table_name(table_name)} CASCADE"
            end
        end
    end
end