Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
832 views
in Technique[技术] by (71.8m points)

c# - Linq query DateTime.Date.DayOfWeek

Trying to get only Thursdays of 1 year back

using (var context = new Context1())
{
      // Get 1 year back only Thursday
      var oneYearEarlier = DateTime.Now.AddYears(-1);

      var query = (from c in context.Daily25Data
                   where c.Date > oneYearEarlier && c.Date.DayOfWeek == DayOfWeek.Thursday
                   select c).ToList();

      Console.WriteLine(query);
}

and getting

Additional information: The specified type member 'DayOfWeek' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

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;

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...