Multi Tenant Service API for Business entities and Business logic

Question

We have an application where we wish to expose an large number of database entities and some business logic. Each entity will require the ability to Read , Add, and Update. at this point we do not expect to allow deletion.

the software we build is used in a wide range of business, so of which are multi tenanted operations Bureau services, also some of our clients use this approach to have separate databases for financial reasons.

We wish to be able to minimize the number of endpoints that need to be maintained. At the moment there are only 3 tables be exposed as WCF interfaces each with 6 attached methods. this is manageable but if operation has 50 databases that suddenly becomes 150 endpoints. worse if we have 50 tables exposed that becomes 2500 endpoints.

Does anyone have a suggestion on how we could design out system that we still have a simple entity model of Job.add (var1) or iList jobs = Job.GetSelected("sql type read").

without all these endpoints

Answer 1

WCF Data Services allows you to expose your data in a RESTful manner using the Open Data protocal (OData). This was formally called ADO.Net data services and before that Astoria. Any IQueryable collection can be exposed. The way shown in most of the examples is to use the Entity Framework, however there are examples showing usage with NHibernate and other Data Access technologies. OData is a self describing API based on Atom-Pub with some custom extensions. With a minimal amount of code you can expose you're entire database in a well defined format. That's the easy part.

In order to implement multi-tenency, you can create query interceptors in the WCF Data Services application to implement that logic. The number of interceptors and the complexity of the code you write will depend upon your security model and requirements. Looking at something like T4 templates or CodeSmith to generate the interceptor methods based on your database schema may be a way to prevent lots of repetitive manual coding.

The link I provided has a lot of information and tutorials on WCF Data Services and would provide a good place to start to see if it would meet your needs. I have been looking at WCF Data Services for a similar problem (Multi-tenancy), and would love to hear how you evently implement your solution.