Model Class: D_Studentgrade_Groupsort.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using SnapObjects.Data;
using DWNet.Data;
using Newtonsoft.Json;
using System.Collections;

namespace Appeon.ApiDoc.Models
{
    [DataWindow("d_studentgrade_groupsort", DwStyle.Default)]
    [Table("StudentGrade")]
    #region DwSelectAttribute  
    [DwSelect("PBSELECT( VERSION(400) TABLE(NAME=\"StudentGrade\" ) @(_COLUMNS_PLACEHOLDER_) )")]
    #endregion
    [DwSort("courseid A")]
    [DwGroupBy(1, "courseid", SortBy = "count(studentid for group 1) A")]
    [DwKeyModificationStrategy(UpdateSqlStrategy.DeleteThenInsert)]
    [UpdateWhereStrategy(UpdateWhereStrategy.KeyAndConcurrencyCheckColumns)]
    public class D_Studentgrade_Groupsort
    {
        [Key]
        [Identity]
        [DwColumn("StudentGrade", "EnrollmentID")]
        public int Enrollmentid { get; set; }

        [ConcurrencyCheck]
        [DwColumn("StudentGrade", "CourseID")]
        public int Courseid { get; set; }

        [ConcurrencyCheck]
        [DwColumn("StudentGrade", "StudentID")]
        public int Studentid { get; set; }

        [ConcurrencyCheck]
        [DwColumn("StudentGrade", "Grade")]
        public decimal? Grade { get; set; }

    }

}