c# - Repository call throws an error in .Net core 3.1

Question

I am trying to export an excel using EPPlus 5.0.4 and it works fine in QA and UAT environment, whereas in Prod it is taking so much time. It seems like the calculation I do using the foreach loop takes time. So I refactored the code and made the changes in the repository call. The repo call returns a List of model by taking a List of model as input. I am using the .Net Core 3.1 version and my repo call gives me an error. I tried using IEnumerable and then converted to list and that threw the same error. I don't want to use foreach loop as it takes so much time. How to rectify this error. Any suggestions would be helpful.

  public List<StagingProductModel> GetStagingProductDetails(List<ProductModel> productModels)
 {
   List<StagingProductModel> stagingProductModel = (from prod in _entity.StagingProduct
                                                 join cust in _entity.Customer on prod.CustomerId 
                                                 equals cust.CustomerId
                                                 where productModels.Any(x => x.ISBN13 == 
                                                  prod.Isbn13 && x.CustomerID == prod.CustomerId)
                                                  select new StagingProductModel
                                                     {
                                                         ProductId = prod.Id,
                                                         ISBN13 = prod.Isbn13,
                                                         ISBN10 = prod.Isbn10,
                                                         CustomerID = cust.CustomerId,
                                                         Author = prod.Author,
                                                         Title = prod.Title,
                                                         PublicationDate = prod.PublicationDate,
                                                         CopyRightYear = prod.CopyRightYear,
                                                         Edition = prod.Edition,
                                                         Comments = prod.Comments,
                                                         StagingProductProperties = (from prodproperty in 
                                                         _entity.StagingProductProperty
                                                         join property in 
                                                         _entity.StagingMasterProperty on 
                                                          prodproperty.PropertyId equals 
                                                          property.Property where 
                                                          prodproperty.ProductId == prod.Id
                                                          select new 
                                                          StagingProductPropertyModel
                                                          {
                                                           ProductId = prod.Id,
                                                           PropertyId = prodproperty.PropertyId,
                                                           Value = prodproperty.PropertyValue,
                                                           PropertyName =  property.PropertyName
                                                          }).ToList(),
                                                     }).ToList();
      }

I get the following error.

   The LINQ expression 'DbSet<StagingProduct>
   .Join(
   outer: DbSet<Customer>,
   inner: s => s.CustomerId,
   outerKeySelector: c => c.CustomerId,
   innerKeySelector: (s, c) => new TransparentIdentifier<StagingProduct, Customer>(
       Outer = s,
       Inner = c
   ))
.Where(ti => __proudctModels_0
   .Any(x => x.ISBN13 == ti.Outer.Isbn13 && x.CustomerID == ti.Outer.CustomerId))' could not be 
 translated. Either rewrite the query in a form that can be translated, or switch to client 
 evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), 
 or ToListAsync().



  

question from:https://stackoverflow.com/questions/65917913/repository-call-throws-an-error-in-net-core-3-1

Answer 1

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