Question

有两个实体，如bellow：

public class Business
{
    public int Id {get; set;}

    public File Logo {get; set;}
    public int? LogoId {get; set;}

    public File Video {get; set;}
    public int? Video {get; set;}

    public ICollection<File> Images {get; set;}
}

public class File
{
    // some file props, such as Id, Name, ...
}

如何为业务删除文件配置级联删除？请注意，我不需要从File到Business的任何导航。

更新：

您可以在下面找到modelBuilder配置：

        modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();

        modelBuilder.Entity<Entities.Business>()
            .HasOptional(b => b.Logo)
            .WithOptionalPrincipal()
            .WillCascadeOnDelete();

        modelBuilder.Entity<Entities.Business>()
            .HasOptional(b => b.Video)
            .WithOptionalPrincipal()
            .WillCascadeOnDelete();

        modelBuilder.Entity<Entities.Business>()
            .HasMany(b => b.Images)
            .WithOptional()
            .WillCascadeOnDelete();

这是我遇到的错误：

引入FOREIGN KEY约束表'文件'上的'FK_dbo.Files_dbo.Businesses_Business_Id1'可能导致循环或多个级联路径。指定ON DELETE NO ACTION或ON 更新无操作，或修改其他FOREIGN KEY约束。不能创建约束

Answer 1

如果你想使用单独的配置类，你可以试试这样的东西：

  public class BusinessConfiguration : EntityTypeConfiguration<Business>
  {
        public BusinessConfiguration()
        {
            HasMany(x => x.Images).WithOptional().WillCascadeOnDelete();
            HasOptional(x => x.Logo).WithOptional().WillCascadeOnDelete();
            HasOptional(x => x.Video).WithOptional().WillCascadeOnDelete();
        }
  }

如果您未在.WithOptional()或.WithRequired()内传递lambda，则表示另一方没有导航属性。

实体框架：如何在单向相关实体上启用级联删除

1 个答案: