Question

有我的简单模型：

class User
{
public ICollection<BusinessCard> BusinessCards { get; set; }    
public ICollection<BusinessCardExtension> BusinessCardsForMe { get; set; }
}

class BusinessCard
{
public  ApplicationUser User { get; set; }
public string UserId { get; set; } 

public ICollection<BusinessCardExtension> ForUsers { get; set; }
}

//it is the class for introducing of many-to-many relationship:
class BusinessCardExtension
{
public string UserId { get; set; }
public ApplicationUser User { get; set; }

public string BusinessCardID { get; set; }
public BusinessCard BusinessCard { get; set; }
}

我需要User和BusinessCard之间的一些关系：一个是一对多，另一个是多对多。从概念上讲，他们是不同的关系。

由于从User到BusinessCardExtension有双重级联路径，我将如下配置ModelBuilder：

       //just configure many-to-many...
       builder.Entity<BusinessCardExtension>()
        .HasKey(b => new { b.UserId, b.BusinessCardID });

       builder.Entity<BusinessCardExtension>()
        .HasOne(b => b.BusinessCard)
        .WithMany(c => c.ForUsers)
        .HasForeignKey(b => b.BusinessCardID);

       builder.Entity<BusinessCardExtension>()
         .HasOne(b => b.User)
         .WithMany(u => u.BusinessCardsForMe)
         .HasForeignKey(b => b.UserId);

       //then to disable double cascade deletion:
       builder.Entity<BusinessCard>()
         .HasOne(c => c.User)
         .WithMany(u => u.BusinessCards)
         .HasForeignKey(c => c.UserId)  
         .OnDelete(DeleteBehavior.Restrict);

然而它没有帮助。 Shell返回错误：

引入FOREIGN KEY约束＆＃39; FK_BusinessCardExtension_Users_UserId＆＃39;桌子上＆＃39; BusinessCardExtension＆＃39;可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他 FOREIGN KEY约束。

EF Core中的级联删除问题

0 个答案: