jonatw/shortUrl — comment on commit 7318bfe6aaa5a5cf688379756ad7cdaa1002e376
File: db/migrate/20111227194032_create_url_data.rb line 8
By marsz:

if u add "t.timestamp"
rails will add tow columns: "created_at" & "updated_at" (both are datetime)
and update current time as data creating and updating
it is not necessary to add urlCreatetime