减少从Silverlight应用到数据库的旅行次数

Question

I am working on a silverlight application. It have a view which allows user to add a new object. The viewmodel bound to this view has a collection of that object type as a property. The constructor of viewmodel has a function, say GetData() that calls a WCF Service and fetches data from database, which adds the fetched list to that collection.

After adding a new object to database through WCF Service, the method GetData needs to be called again to refresh the collection as having the latest data in collection is necessary.

This process is a little slow as every time one adds anything, entire data from the tables need to be fetched again. It can get even more slower as data grows more and more large and when joining of multiple tables may be required to get the data.

I am thinking of adding the object that I pass to service to add it to database, directly to the collection in viewmodel. Obviously, I will add this object to the collection only when service called to it has not returned any error to make sure it has been successfully added to DB. This way I can have the latest data in collection without any need to fetch it from database.

Can any one point out any drawback with this approach or any scenario where it may fail? Also, please suggest if there are other better ways of achieving this goal.

Answer 1

I often have my save methods fetch and return the object that was saved. That way if the service/DB layer has modified it at all (create date, ID etc. etc.) you get the changes. Also if you want to update it, it does not think it is "new".