code: function onupgradeneeded() {
              self.db = request.result;
              self.transaction = request.transaction;
  
              // NB! in case of a version conflict, we don't try to migrate,
              // instead just throw away the old store and create a new one.
              // this happens if somebody changed the 
              try {
                  self.db.deleteObjectStore(self.record);
              } catch (e) { /* ignore */ }
  
              // create object store.
              var objectStoreOptions = {
                  autoIncrement: useAutoIncrement()
              }
              if( typeof( self.keyPath )) {
                  objectStoreOptions.keyPath = self.keyPath;
              }
              self.db.createObjectStore(self.record, objectStoreOptions);
          }
docs: first start or indexeddb needs a version upgrade