Question

我正在编写一个MVC 3项目，我正在使用实体框架。我编写了一个生成批量数据库条目的方法，这是针对客户的发票。该系统适用于大学，每个学生都在注册课程中注册了一名特定的导师。此注册的月费存储在注册中。发票方法可以正常生成发票，但现在我希望为学院的导师生成佣金单的数据库条目。该方法需要找到所有与每位导师一起注册的学生（通过注册课程）并积累这一数额。然后将这一总额乘以导师收到的佣金百分比。这将是CommissionAmount。我不确定如何为此编写代码。这些是相关的模型类：

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 long 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 TutorCommissionPercentage
{
    [Key]
    public int TutorCommissionID { get; set; }
    public long TutorNoID { get; set; }
    [Range(0, 100, ErrorMessage="Percentage must be between 0 and 100")]
    [Display(Name="Commission Percentage")]
    public decimal CommissionPercentage { get; set; }

    public virtual Tutor Tutor { get; set; }
}

生成发票的代码如下：

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

        var enrolments = db.Enrollments.ToList();

        var newInvoices = from enrolment in enrolments
                          select new Invoices()
                          {
                              InvoiceAmount = enrolment.MonthlyFee,
                              InvoiceMonth = month,  // string constant
                              InvoiceStatus = "Unpaid",
                              ClientNumberID = enrolment.ClientNumberID
                          };

        foreach (var newInvoice in newInvoices)
        {
            db.Invoice.Add(newInvoice);
            db.SaveChanges();
        }

        return RedirectToAction("Index");
    }

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; }

}

这些批量数据库输入方法的目的是让经理可以点击一个链接，为数据库中的所有客户和导师生成发票和佣金单。

谢谢艾米

Answer 1

要在一个声明中完成所有操作，您需要加入注册和佣金，然后由导师分组。

第一个示例使用了您正在使用的查询语法：

        IEnumerable<TutorCommission> tutorsCommissions =
            from enrollment in enrollments // Take the enrollments
            join tutorsCommissionPercentage in tutorCommissionPercentages // Join with the tutor's commission percentages.
                on enrollment.TutorNoID equals tutorsCommissionPercentage.TutorNoID
            group enrollment by new { enrollment.TutorNoID, tutorsCommissionPercentage.CommissionPercentage } into enrollmentsAndCommissionByTutor // group enrollments and commission by the tutor
            select new TutorCommission
            {
                TutorNoID = enrollmentsAndCommissionByTutor.Key.TutorNoID, // the grouping which is the tutor
                CommissionAmount = (long) enrollmentsAndCommissionByTutor.Sum(e => e.MonthlyFee * enrollmentsAndCommissionByTutor.Key.CommissionPercentage)
            };

第二个示例使用方法语法，这个操作更直观

        IEnumerable<TutorCommission> tutorsCommissionsAlt = enrollments // Take the enrollments
            .GroupJoin( // This will group enrollments by the tutor
                tutorCommissionPercentages, // 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.CommissionPercentage * e.MonthlyFee)
                });

批量数据库条目 - 计算佣金

1 个答案: