“Injecting” a WHERE clause dynamically w/ PetaPoco

Question

I'm building a multi-tenant app with a shared database using .NET MVC 3 and PetaPoco. The tenant id (along with other info) is saved in a FormsAuth cookie on login and is available to all controllers via a BaseController property. Most tables, (i.e. apart from apart the main 'Tenants' table) include a TenantId column.

Instead of manually adding a 'WHERE TenantId = X' to all CRUD on the feature tables, is there a way I can dynamically add this to the query just before its executed? In other words, maybe maintain a list of tables, and if the query is for one of those tables, then dynamically add in the TenantId filter?

The benefit of course is that it removes the need to add in the filter manually thus reducing the chances its left out. I did find an example using NHibernate, which I doubt can be repurposed. I am using Ninject in case that makes a difference.

Answer 1

There is an OnCommandExecuting method on the Database class which you can override in your own sub class, and modify the sql as you wish just before it gets executed. We use this feature for converting isnull/nvl between Sql Server and Oracle.

You could just leave a marker in your sql and replace it here.