外键约束可能导致循环或多个级联路径 ASP.NET Core MVC

Question

我正在使用 ASP.NET Core MVC 做一个项目。 我创建了我的模型，当我更新迁移时，我得到了这个错误。

在表 'Branch' 上引入 FOREIGN KEY 约束 'FK_Branch_Countries_CountriesId' 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

我浏览了代码，希望分配的外键没有问题。

我希望问题是Branch和Country都包含外键的CountryId 。 它应该连接到与Country表相连的两个表。 但是这里它说由于循环或多个级联路径而无法创建表。

那么如何避免这种情况并进行迁移呢？ 还是我连接 3 个表的方式不对？

你能帮我解决这个问题吗？

public class Countries
{
    [Key]
    public int Id { get; set; }
    [Required]
    public string Country_Name { get; set; }
    public string Country_Code { get; set; }
    public string Note { get; set; } = "N/A";
    public bool Status { get; set; } = true;
    public DateTime CreatedDate { get; set; } = DateTime.Now;
    public int CreateBy { get; set; }
    public DateTime ModifiedDate { get; set; } = DateTime.Now;
    public int ModifiedBy { get; set; }

    public virtual IList<Province> Province { get; set; }
    public virtual IList<Branch> Branch { get; set; }

    public Countries()
    {
        Province = new List<Province>();
        Branch = new List<Branch>();
    }
}

public class Province
{
    [Key]
    public int Id { get; set; }
    [Required]
    public string Province_Name { get; set; }
    public string Province_Code { get; set; }
    [Required]
    [ForeignKey("Countries")]
    public int Country_Id { get; set; }
    public virtual Countries Countries { get; set; }
    public string Note { get; set; } = "N/A";
    public bool Status { get; set; } = true;
    public DateTime CreatedDate { get; set; } = DateTime.Now;
    public int CreateBy { get; set; }
    public DateTime ModifiedDate { get; set; } = DateTime.Now;
    public int ModifiedBy { get; set; }

    public virtual IList<Cities> Cities { get; set; }
    public virtual IList<Branch> Branch { get; set; }

    public Province()
    {
        Cities = new List<Cities>();
        Branch = new List<Branch>();
    }
}

public class Cities
{
    [Key]
    public int Id { get; set; }
    public string City_Name { get; set; }
    [ForeignKey("Province")]
    public int Province_Id { get; set; }
    public virtual Province Province { get; set; }
    public string Postal_Code { get; set; }
    public string Istat_Code { get; set; }
    public string Note { get; set; } = "N/A";
    public bool Status { get; set; } = true;
    public DateTime CreatedDate { get; set; } = DateTime.Now;
    public int CreateBy { get; set; }
    public DateTime ModifiedDate { get; set; } = DateTime.Now;
    public int ModifiedBy { get; set; }

    public virtual IList<Branch> Branch { get; set; }

    public Cities()
    {
        Branch = new List<Branch>();
    }
}

public class Branch
{
    [Key]
    public int Id { get; set; }
    public string BranchName { get; set; }
    public string Note { get; set; }
    public int City_Id { get; set; }
    public virtual Cities Cities { get; set; }
    public int Province_Id { get; set; }
    public virtual Province Province { get; set; }
    public int Country_Id { get; set; }
    public virtual Countries Countries { get; set; }
    public string LocationEmailAddress { get; set; }
    public string LocationContactNumber { get; set; }
    public bool Status { get; set; } = true;
    public DateTime CreatedDate { get; set; } = DateTime.Now;
    public int CreateBy { get; set; }
    public DateTime ModifiedDate { get; set; } = DateTime.Now;
    public int ModifiedBy { get; set; }

    public virtual IList<EmployeeLocations> EmployeeLocations { get; set; }

    public Branch()
    {
        EmployeeLocations = new List<EmployeeLocations>();
    }
}

Answer 1

它是由多个级联路径引起的：

分公司-国家-省-市

分省市

分城

您可以查看此案例以获取更多详细信息： 外键约束可能导致循环或多个级联路径？

Answer 2

解决方案非常简单。 您应该从Branch中删除ContryId ，因为ContryId已在Province中引用。