配置级联删除

Question

I have 8 objects which reference a generic entity called ExpenseType. There are 36 references to ExpenseType between the 8 objects. I'd like to configure cascade delete so that when the referencing objects are deleted, so too are the ExpenseType records.

I'm using Code First Entity Framework 5 and have already done this for other objects in my schema, but the generic nature of this has me stumped.

Any and all help is greatly appreciated.

Thanks John

public class HouseholdExpenses
    {
        [Key]
        public virtual int HouseholdExpensesId { get; set; }

        [Display(Name = "Childcare")]
        public virtual ExpenseType Childcare { get; set; }

        [Display(Name = "Elderly Care (Carer Nursing Home etc)")]
        public virtual ExpenseType ElderlyCare { get; set; }

        [Display(Name = "Food / Housekeeping / Personal Care")]
        public virtual ExpenseType FoodHousekeeping { get; set; }

        [Display(Name = "Clothing and Footwear")]
        public virtual ExpenseType ClothingFootwear { get; set; }

        [Display(Name = "House Repairs and Maintenance")]
        public virtual ExpenseType RepairsAndMaintenance { get; set; }
}

    public class MedicalExpenses
    {
        [Key]
        public virtual int MedicalExpensesId { get; set; }

        [Display(Name = "Medical Expenses and Prescription Charges")]
        public virtual ExpenseType MedicalExpensesAndPrescriptions { get; set; }

        [Display(Name = "Health Insurance (unless deducted from your salary at source)")]
        public virtual ExpenseType HealthInsurance { get; set; }
}

public class ExpenseType
{
    [Key]
    public virtual int ExpenseTypeId { get; set; }

    [Display(Name = "Amount")]
    public virtual decimal? Amount { get; set; }

    [Display(Name = "Arrears")]
    public virtual decimal? Arrears { get; set; }
}

Answer 1

Override OnModelCreating and try this. Unless I am forgetting something I think it should work.

mBuilder.Entity<ExpenseType>()
            .HasRequired(he => he.Childcare)
            .WithMany();

mBuilder.Entity<ExpenseType>()
            .HasRequired(ec => ec.ElderlyCare)
            .WithMany();
...