EF Code First 级联删除和更新？

Question

我的实体是这些：

public class Customer
{
    public Customer()
    {
        Invoices = new List<Invoice>();
        Payments = new List<Payment>();
    }

    public int ID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    public IList<Payment> Payments { get; set; }
}

public class Payment
{
    public int ID { get; set; }
    public int CustomerID { get; set; }
    public decimal CreditPrice { get; set; }
    public decimal DebitPrice { get; set; }
    public DateTime PaymentDate { get; set; }

    [ForeignKey("CustomerID")]
    public Customer Customer { get; set; }
}

这是我的背景：

public class AccountingContext : DbContext, IDisposable
{
    public DbSet<Customer> Customers { get; set; }
    public DbSet<Payment> Payments { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

        modelBuilder.Entity<Payment>()
                .HasRequired(s => s.Customer)
                .WillCascadeOnDelete();

        base.OnModelCreating(modelBuilder);
    }
}

我在WillCascadeOnDelete() 中收到此错误：

错误 1“System.Data.Entity.ModelConfiguration.Configuration.RequiredNavigationPropertyConfiguration”不包含“WillCascadeOnDelete”的定义并且没有接受“System.Data.Entity.ModelConfiguration.Configuration.RequiredNavigationPropertyConfiguration”类型的第一个参数的扩展方法“WillCascadeOnDelete”可以找到（您是否缺少 using 指令或程序集引用？） D​​:\\Work\\C# Projects\\Visual Studio 2010\\Windows\\WPF\\New folder\\Accounting without EF Code First\\Accounting - Copy\\DAL.EF.CodeFirst \\Entities\\Context\\AccountingContext.cs 22 22 DAL.EF.CodeFirst

我想删除客户级联的付款（如果客户被删除）。 我怎样才能首先在 EF 代码中实现这一点？

我也想使用级联更新。 请帮助我解决这些问题。 谢谢。

Answer 1

描述

您需要在上下文中配置modelBuilder。

样品

public class AccountingContext : DbContext, IDisposable
{
    public DbSet<Customer> Customers { get; set; }
    public DbSet<Payment> Payments { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

        modelBuilder.Entity<Payment>()
                .HasRequired(s => s.Customer)
                .WithMany()
                .WillCascadeOnDelete(true);

        base.OnModelCreating(modelBuilder);
    }
}

Answer 2

在模型创建方法上，您需要进行如下更改

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
            //Disabling Delete Cascade
            foreach (var foreignKey in modelBuilder.Model.GetEntityTypes().SelectMany(model=>model.GetForeignKeys()))
            {
                //Disabling Delete Cascade on Each Entities
                foreignKey.DeleteBehavior = DeleteBehavior.Restrict;
            }
}