Question

I have 3 entities, users, tasks and permissions. Users can have many permissions. Tasks also have many permission associated with them. The idea that I am trying to capture in my query is this: My tasks need to be done by users with all the correct permissions required by the task.

I am struggling with the query. I think this is what I need:

var userList = context.Users
                      .Include("Permissions")
                      .Where(x => neededPermissionFromTask.Except(x.Permissions).Count() == 0).ToList();

But I get an exception:

Unable to create a constant value of type ‘Permission’. Only primitive
types (‘such as Int32, String, and Guid’) are supported in this
context.

Appreciate any help, suggestions or comments.

Answer 1

Instead of passing list of Permission objects, pass ids of those permissions:

var ids = neededPermissionFromTask.Select(p => p.Id).ToList();
var userList = 
     context.Users.Include("Permissions")
            .Where(u => ids.Except(u.Permissions.Select(p => p.Id)).Count() == 0)
            .ToList();