Rails 2.3 私が試したこと...
>> Import::Subscription.all(:conditions => ["account_id = ?", "44"]).destroy_all
NoMethodError: undefined method 'destroy_all' for #<Array:0x106ab4d78>
>> Import::Subscription.all(:conditions => ["account_id = ?", "44"])
>> @subs = _
>> @subs.each { |s| s.destroy }
ActiveRecord::StatementInvalid: Mysql::Error: Cannot delete or update a parent row: a
foreign key constraint fails
@subs[0].delete
ActiveRecord::StatementInvalid: Mysql::Error: Cannot delete or update a parent row: a
foreign key constraint fails