Linq query DateTime.Date.DayOfWeek

Question

Trying to get only Thursdays of 1 year back

using (var context = new Context1())
{
      // Get 1 year back only Thursday
      var oneYearEarlier = DateTime         


        

Answer 1

LINQ will not recognize the second part of your query into SQL. You need to break your query up in order to perform the filter.

using (var context = new algoventurelab_db1Context())
{
      // Go one year back from current date
      var startDate = DateTime.Today.AddYears(-1);
      // This will get all dates in context greater than start date.
      var query1 = (from c in context.Daily25Data
                   where c.Date >= startDate
                   select c).AsEnumerable();
      //this will filter only thurdays
      var query = from c in query1
                  where c.Date.DayOfWeek == DayOfWeek.Thursday
                  select c).ToList();

      Console.WriteLine(query);
}

Answer 2

This is a clever solution using EntityFunctions.DiffDays

from his post:

DateTime firstSunday = new DateTime(1753, 1, 7); 
var bookings = from b in this.db.Bookings 
               where EntityFunctions.DiffDays(firstSunday, b.StartDateTime) % 7 == 1 
               select b;