Unable to create a constant value - only primitive types

Question

Two simple queries - the exception occurs in :

matchings.Any(u => product.ProductId == u.ProductId)

What is wrong? If I write true

Answer 1

I was facing the same issue when writing the following query using collection and EF tables:

var result = (from listItem in list
              join dbRecord in Context.MY_TABLE
                  on listItem.MyClass.ID equals dbRecord.ID
              select new { dbRecord, listItem.SomeEnum }).ToList();

I could solve it by changing the source order in in:

var result = (from dbRecord in Context.MY_TABLE
              join listItem in list
                  on dbRecord.ID equals listItem.MyClass.ID
              select new { dbRecord, listItem.SomeEnum }).ToList();