得到“无法翻译。 以可翻译的形式重写查询”，.NET Corel 中的异常

Question

I am working on a C# application. I have to create a predicate for filtering data. I have a model class TissueItem which has a property named ExpirationData . I have to get that data from TissueItem where expiration date is less than or equal to number specified. My predicate expression is:

ExpressionStarter<TissueItem> predicate = PredicateBuilder.New<TissueItem>();
predicate = predicate.And(x => 
    Convert.ToInt32((x.ExpirationDate.Value - DateTime.Today).TotalDays) 
       <= inventorySearchFilterModel.ExpirationStatus);

When i pass this predicate to get the data, i am getting the following exception:

The LINQ expression 'DbSet<TissueItem>()
    .Where(t => Convert.ToInt32((t.ExpirationDate.Value - DateTime.Today).TotalDays) <= __inventorySearchFilterModel_ExpirationStatus_0)' 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 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'.

What can be the possible issue. I am using .NET Core 3.1.

Answer 1

Try this variant. Looks like EFC do not handle Timestamp.TotalDays .

var predicate = PredicateBuilder.New<TissueItem>();
predicate = predicate.And(x => 
    EF.Functions.DateDiffDay(x.ExpirationDate.Value, DateTime.Today) 
       <= inventorySearchFilterModel.ExpirationStatus);