// Query a list of people, print out the properties of Person, // Student and BusinessStudent public static void Query() { using (EFTPHEntities context = new EFTPHEntities()) { var people = from p in context.People select p; foreach (var p in people) { Console.WriteLine("Student {0} {1}", p.LastName, p.FirstName); if (p is Student) { Console.WriteLine("EnrollmentDate: {0}", ((Student)p).EnrollmentDate); } if (p is BusinessStudent) { Console.WriteLine("BusinessCredits: {0}", ((BusinessStudent)p).BusinessCredits); } } } }
// 查询people类型的列表, 输出Person, Student和BusinessStudent的属性 public static void Query() { using (EFTPHEntities context = new EFTPHEntities()) { var people = from p in context.People select p; foreach (var p in people) { Console.WriteLine("Student {0} {1}", p.LastName, p.FirstName); if (p is Student) { Console.WriteLine("EnrollmentDate: {0}", ((Student)p).EnrollmentDate); } if (p is BusinessStudent) { Console.WriteLine("BusinessCredits: {0}", ((BusinessStudent)p).BusinessCredits); } } } }