c# - 如何在 LINQ to entities 中使用 Date 函数？

Question

我的方法应该返回一个用户注释列表，所以我这样做了:

  var saturday = DayOfWeek.Saturday;
  var query = from note in userNotes
  where note.NoteDate > lastMonth && note.NoteDate.DayOfWeek != saturday
        select note;

但是我得到这个错误:

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

关于如何使用 linq 比较星期几的任何想法？

Answer 1

使用SqlFunctions.DatePart静态方法。它将转化为DATEPART TSQL 函数调用。

var saturday = (int)DayOfWeek.Saturday;
var query = from note in userNotes
            where note.NoteDate > lastMonth && SqlFunctions.DatePart("dw", note.NoteDate) != saturday
            select note;