EF错误无法创建类型为“匿名类型”的常量值。 在此上下文中仅支持原始类型或枚举类型

Question

I m querying some collections and then converting my result to JSON but getting below error:

Unable to create a constant value of type 'Anonymous type'. Only primitive types or enumeration types are supported in this context

Below is my code, please guide & help me.

  var AllStatus = RepositoryFactory.OrderStatusRepository.GetAll().AsEnumerable().Select(s => new
            {
              Status =  s.Status,
               StatusId= s.Id
            });

            var AllUsers = RepositoryFactory.UserRepository.GetAll().AsEnumerable().Select(u => new
            {
                UserId= u.UserId,UserName=u.UserName 
            });

            var result = RepositoryFactory.OrderHistoryRepository.GetAll().Select(v => new
            {
                PatientId = v.UserId ,
                UserName = AllUsers.Where(u=>u.UserId==v.UserId).Select(u=>u.UserName),
                Status = AllStatus.Where(s=>s.StatusId==v.OrderStatusId).Select(s=>s.Status),
                StatusDate = v.UpdatedDate,
                Amount = v.Amount  
            }) ; 


            returnModel.Data = result.ToJSON();

thanks

Answer 1

1. Parts of code: AllUsers.Where(u=>u.UserId==v.UserId).Select(u=>u.UserName) and AllStatus.Where(s=>s.StatusId==v.OrderStatusId).Select(s=>s.Status) return IEnumerable<string> , and you need, I guess, single string ;
2. Instead Select method, use ToDictionary

var AllStatus = RepositoryFactory.OrderStatusRepository.GetAll().AsEnumerable()
               .ToDictionary(x=> x.Id, x=> x.Status);

var AllUsers = RepositoryFactory.UserRepository.GetAll().AsEnumerable()
              .ToDictionary(u => u.UserId, u=> u.UserName);

var result = RepositoryFactory.OrderHistoryRepository.GetAll()
        .Select(v => new
        {
            PatientId = v.UserId ,
            UserName = AllUsers.ContainsKey(v.UserId) ? AllUsers[v.UserId] : null,
            Status = AllStatus.ContainsKey(v.StatusId) ? AllUsers[v.StatusId] : null,
            StatusDate = v.UpdatedDate,
            Amount = v.Amount  
        }) ;