WCF Service call to multiple rows. How to architecture it?

Question

Hi,

Let's say I have a scenario where I have a Service that is responsible for retrieving the price of a single product given the ID and another Service that gives me the current stock position of it.

It's okay when I'm looking only at one product, but what about a list page where I have 60 products? What should I do in this case? Call the service product by product to retrieve it's current price and stock position?

I think this would be extremely slow and cost a lot of resources. But what could I do to make it look good and at the same time have performance?

Currently we have these information in the database in a column next to the product. These price and stock columns are updated by a sql service that updates it when is necessary so when I need to grab the value for a lot of products at the same time I just need to select two columns more. It's really fast, but right now we have some more systems in need of this information and I would like to transform all these stuff in a service.

Thanks a lot!

Answer 1

Well, you could always have multiple service methods:

• the one you already have, to retrieve a single product, and the price for a single product
• create a new service method which would take a list of product ID's, and return a list of product objects - or a new DTO (data-transfer object) that holds product and price

This way, you could keep your current users happy, and also do something to make batch requests work more efficiently.

Answer 2

Can your service method take an array of IDs? And return an array of values? That way if you want one record your array only has 1 item, if you want more, you just populate the array with multiple values?