C# – “The specified type member ‘Date’ is not supported in LINQ “

centity-frameworklambdalinq

_dbEntities.EmployeeAttendances.Where(x => x.DailyDate.Date.Equals(DateTime.Now.Date)).ToList();

"The specified type member 'Date' is not supported in LINQ to
Entities. Only initializers, entity members, and entity navigation
properties are supported."

How can i do this get employees data on based on current date in linq query?

Best Answer

EntityFramework cannot convert DateTime.Date to SQL. So, it fails to generate expected SQL. Instead of that you can use EntityFunctions.TruncateTime() or DbFunctions.TruncateTime()(based on EF version) method if you want to get Date part only:

 _dbEntities.EmployeeAttendances
            .Where(x => EntityFunctions.TruncateTime(x.DailyDate) == DateTime.Now.Date)
            .ToList();

Additional info:

EntityFunctions methods are called canonical functions. And these are a set of functions, which are supported by all Entity Framework providers. These canonical functions will be translated to the corresponding data source functionality for the provider. Canonical functions are the preferred way to access functionality outside the core language, because they keep the queries portable.

You can find all canonical functions here and all Date and Time Canonical Functions here.

Update:

As of EF6 EntityFunctions has been deprecated for System.Data.Entity.DbFunctions.

Related Solutions

C# – LINQ’s Distinct() on a particular property

What if I want to obtain a distinct list based on one or more properties?

Simple! You want to group them and pick a winner out of the group.

List<Person> distinctPeople = allPeople
  .GroupBy(p => p.PersonId)
  .Select(g => g.First())
  .ToList();

If you want to define groups on multiple properties, here's how:

List<Person> distinctPeople = allPeople
  .GroupBy(p => new {p.PersonId, p.FavoriteColor} )
  .Select(g => g.First())
  .ToList();

Note: Certain query providers are unable to resolve that each group must have at least one element, and that First is the appropriate method to call in that situation. If you find yourself working with such a query provider, FirstOrDefault may help get your query through the query provider.

Note2: Consider this answer for an EF Core (prior to EF Core 6) compatible approach. https://stackoverflow.com/a/66529949/8155

C# – Using LINQ to remove elements from a List

Well, it would be easier to exclude them in the first place:

authorsList = authorsList.Where(x => x.FirstName != "Bob").ToList();

However, that would just change the value of authorsList instead of removing the authors from the previous collection. Alternatively, you can use RemoveAll:

authorsList.RemoveAll(x => x.FirstName == "Bob");

If you really need to do it based on another collection, I'd use a HashSet, RemoveAll and Contains:

var setToRemove = new HashSet<Author>(authors);
authorsList.RemoveAll(x => setToRemove.Contains(x));

Best Answer

Related Solutions

C# – LINQ’s Distinct() on a particular property

C# – Using LINQ to remove elements from a List

Related Topic