C# 一个数据库条目中的总金额-MVC 3

我写了一个方法，在一个大学的系统中为导师生成佣金单。导师让某些学生以每月一定的费用与他们一起注册，并且他们可以从他们提供的课程中获得佣金。使用此方法，我试图计算属于导师的所有注册的总金额（即，如果他们有3名学生，每个学生每月注册R460，总金额将为1380乘以他们的佣金百分比）。因此，我希望生成一份佣金单（TutorCommission实体中的一个数据库条目）数据库中每个导师的总金额。以下是代码：

  public ActionResult CreateBulkCommissions()
        {
{
    var month = DateTime.Now.ToString("MMMM");

    var enrolments = db.Enrollments.ToList();
    var tutor = db.Tutors.ToList();

    IEnumerable<TutorCommission> tutorsCommissionsAlt = enrolments // Take the enrollments
        .GroupJoin( // This will group enrollments by the tutor
            tutor, // Join with the tutor's commission percentages.
            e => e.TutorNoID, // Use tutorNoID for left Key
            tcp => tcp.TutorNoID, // ... and right key
            (e, tcp) => new TutorCommission // Create entry which is the tutor and his total commission
            {
                TutorNoID = e.TutorNoID,
                CommissionAmount = (long)tcp.Sum(c => c.TutorCommissionPercentage * e.MonthlyFee),
                CommissionMonth = month,  // string constant 
                CommissionStatus = "Unpaid",
            });

    foreach (var com in tutorsCommissionsAlt)
    {
        db.TutorCommission.Add(com);
        db.SaveChanges();
    }

    return RedirectToAction("Index");
}
        }

public ActionResult（））
{
{
var month=DateTime.Now.ToString（“MMMM”）；
var enrolments=db.enrolments.ToList（）；
var tutor=db.Tutors.ToList（）；
IEnumerable TutorsCommissionAlt=注册//接受注册
.GroupJoin（//这将由导师对注册进行分组
导师，//加入导师的佣金百分比。
e=>e.TutorNoID，//对左键使用TutorNoID
tcp=>tcp.TutorNoID，//…和右键
（e，tcp）=>新建导师委员会//创建导师及其总佣金的条目
{
TutorNoID=e.TutorNoID，
佣金金额=（长）tcp.Sum（c=>c.TutorCommissionPercentage*e.MonthlyFee），
CommissionMonth=month，//字符串常量
佣金状态=“未付”，
});
foreach（导师委员会ALT中的var com）
{
db.TutorCommission.Add（com）；
db.SaveChanges（）；
}
返回操作（“索引”）；
}
}

目前，此代码为每个注册生成一个新的数据库条目（因此，如果他们有20个注册，则将为该月生成20个数据库条目）。我可以对此代码进行哪些更改，以将每个导师的总金额放入一个数据库条目中？以下是相关类：

public class Enrollment
{
    [Key]
    [Display(Name = "Enrollment ID Number")]
    public long EnrollmentIDNumber { get; set; }
    [Display(Name = "Client ID Number")]
    public long ClientNumberID { get; set; }
    [Display(Name = "Tutor ID Number")]
    public long TutorNoID { get; set; }
    [Display(Name = "Course Name")]
    public string CourseName { get; set; }
    [Display(Name = "Lesson Time")]
    public string LessonTime { get; set; }
    [Display(Name = "Lesson Day")]
    public string LessonDay { get; set; }
    [Display(Name = "Lesson Location")]
    public string LessonLocation { get; set; }
    [Display(Name = "Lesson Type")]
    public string LessonType { get; set; }
    [Display(Name = "Lesson Level")]
    public string LessonLevel { get; set; }
    [Display(Name = "Monthly Fee")]
    public long MonthlyFee { get; set; }

    public virtual Client Client { get; set; }
    public virtual Tutor Tutor { get; set; }

}

public class TutorCommission
{
    [Key]
    [Display(Name = "Commission ID")]
    public long CommissionID { get; set; }
    [Display(Name = "Commission Month")]
    public string CommissionMonth {get; set;}
    [Display(Name = "Commission Amount")]
    public double CommissionAmount { get; set; }
    [Display(Name = "Commission Status")]
    public string CommissionStatus { get; set; }
    [Display(Name = "Tutor ID Number")]
    public long TutorNoID { get; set; }

    public virtual Tutor Tutor { get; set; }
    public virtual ICollection<CommissionPayments> CommissionPayments { get; set; }

}

public class Tutor
{
    [Key]
    [Display(Name = "Tutor ID Number")]
    public long TutorNoID { get; set; }
    [Required]
    [StringLength(50, ErrorMessage="First name must be less than 50 characters")]
    [Display(Name = "First Name")]
    public string TutorFirstName { get; set; }
    [StringLength(50, ErrorMessage = "Last name must be less than 50 characters")]
    [Display(Name = "Last Name")]
    public string TutorLastName { get; set; }
    [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)]
    [Display(Name = "Birth Date")]
    public DateTime? TutorBirthDate { get; set; }
    [Display(Name = "Cellphone Number")]
    public string TutorCellphoneNumber { get; set; }
    [Display(Name = "Home Number")]
    public string TutorHomeNumber { get; set; }
    [RegularExpression("^[a-z0-9_\\+-]+(\\.[a-z0-9_\\+-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*\\.([a-z]{2,4})$", ErrorMessage = "Not a valid email address")]
    [Display(Name = "Email Address")]
    public string TutorEmailAddress { get; set; }
    [Display(Name = "Street Address")]
    public string TutorStreetAddress { get; set; }
    [Display(Name = "Suburb")]
    public string TutorSuburb { get; set; }
    [Display(Name = "City")]
    public string TutorCity { get; set; }
    [Display(Name = "Postal Code")]
    public string TutorPostalCode { get; set; }
    [Display(Name="Full Name")]
    public string FullName
    {
        get
        {
            return TutorFirstName + " " + TutorLastName;
        }
    }
    [Display(Name="Commission Percentage")]
    [Required]
    public double TutorCommissionPercentage { get; set; }

    public virtual ICollection<Enrollment> Enrollments { get; set; }
    public virtual ICollection<TutorCommission> TutorCommissions { get; set; }

公共班级注册
{
[关键]
[显示（Name=“注册ID号”）]
公共长注册IDNumber{get；set；}
[显示（Name=“客户ID号”）]
public long clientnumberrid{get；set；}
[显示（Name=“导师ID号”）]
公共长TutorNoID{get；set；}
[显示（Name=“课程名称”）]
公共字符串CourseName{get；set；}
[显示（Name=“课程时间”）]
公共字符串LessonTime{get；set；}
[显示（Name=“课程日”）]
公共字符串LessonDay{get；set；}
[显示（Name=“课程位置”）]
公共字符串LessonLocation{get；set；}
[显示（Name=“课程类型”）]
公共字符串LessonType{get；set；}
[显示（名称=“课程级别”）]
公共字符串LessonLevel{get；set；}
[显示（Name=“月费”）]
公共长月份fee{get；set；}
公共虚拟客户端{get；set；}
公共虚拟导师{get；set；}
}
公共班级辅导委员会
{
[关键]
[显示（Name=“佣金ID”）]
公共长委托ID{get；set；}
[显示（Name=“佣金月”）]
公共字符串CommissionMonth{get；set；}
[显示（Name=“佣金金额”）]
公共双佣金挂载{get；set；}
[显示（Name=“佣金状态”）]
公共字符串CommissionStatus{get；set；}
[显示（Name=“导师ID号”）]
公共长TutorNoID{get；set；}
公共虚拟导师{get；set；}
公共虚拟ICollection佣金支付{get；set；}
}
公开课导师
{
[关键]
[显示（Name=“导师ID号”）]
公共长TutorNoID{get；set；}
[必需]
[StringLength（50，ErrorMessage=“名字必须少于50个字符”）]
[显示（Name=“First Name”）]
公共字符串TutorFirstName{get；set；}
[StringLength（50，ErrorMessage=“姓氏必须少于50个字符”）]
[显示（Name=“Last Name”）]
公共字符串TutorLastName{get；set；}
[DisplayFormat（DataFormatString=“{0:d}”，ApplyFormatInEditMode=true）]
[显示（Name=“出生日期”）]
公共日期时间？TutorBirthDate{get；set；}
[显示（Name=“手机号码”）]
公共字符串TutorCellphoneNumber{get；set；}
[显示（Name=“家庭号码”）]
公共字符串TutorHomeNumber{get；set；}
[RegularExpression（“^[a-z0-9\\+-]+（\\.[a-z0-9\\+-]+）*@[a-z0-9-]+（\\.[a-z0-9-]+）*\.（[a-z]{2,4}$”，ErrorMessage=“不是有效的电子邮件地址”）]
[显示（Name=“电子邮件地址”）]
公共字符串TutorEmailAddress{get；set；}
[显示（Name=“街道地址”）]
公共字符串TutorStreetAddress{get；set；}
[显示（Name=“郊区”）]
公共字符串TutorSuburb{get；set；}
[显示（Name=“City”）]
公共字符串TutorCity{get；set；}
[显示（名称=“邮政编码”）]
公共字符串TutorPostalCode{get；set；}
[显示（Name=“全名”）]
公共字符串全名
{
得到
{
返回TutorFirstName+“”+TutorLastName；
}
}
[显示（Name=“佣金百分比”）]
[必需]
公共双TutorCommissionPercentage{get；set；}
公共虚拟ICollection注册{get；set；}
公共虚拟ICollection TutorCommissions{get；set；}

谢谢，

---

艾米

看起来你的藏书被指定的方式不对-你不应该把一份报名表加入到一个导师的名单中吗

IEnumerable<TutorCommission> tutorsCommissionsAlt = enrolments.GroupJoin(tutor ...

IEnumerable TutorsCommissionAlt=enrolments.GroupJoin（导师。。。

应该是：

IEnumerable<TutorCommission> tutorsCommissionsAlt = tutor.GroupJoin(enrolments...

IEnumerable TutorsCommissionAlt=tutor.GroupJoin（注册。。。

我把这段代码放在一起，它似乎检查出：

        var month = DateTime.Now.ToString("MMMM");

        var enrolments = new List<Enrollment>();
        enrolments.Add(new Enrollment { TutorNoID = 1, MonthlyFee = 1500 });
        enrolments.Add(new Enrollment { TutorNoID = 1, MonthlyFee = 4500 });

        var tutor = new List<Tutor>();
        tutor.Add(new Tutor { TutorNoID = 1, TutorCommissionPercentage = 0.5 });


        IEnumerable<TutorCommission> tutorsCommissionsAlt = tutor.GroupJoin(enrolments,
                tut => tut.TutorNoID, 
                enr => enr.TutorNoID,
                (tut, enr) => new TutorCommission // Create entry which is the tutor and his total commission
                {
                    TutorNoID = tut.TutorNoID,
                    CommissionAmount = (long)enr.Sum(c => c.MonthlyFee * tut.TutorCommissionPercentage),
                    CommissionMonth = month,  // string constant 
                    CommissionStatus = "Unpaid",
                });


        foreach (var com in tutorsCommissionsAlt)
        {
            Console.WriteLine(com.CommissionAmount);
        }

// Output: 3000

var month=DateTime.Now.ToString（“MMMM”）；
变量注册=新列表（）；
添加（新注册{TutorNoID=1，MonthlyFee=1500}）；
注册。添加（新注册{Tut