Question

我在公司和CompanyDemographics之间建立了1：1的关系，如下所示：

public class Company
{
    public Company()
    {
        Contacts = new HashSet<Contact>();
    }

    [Key]
    public int CompanyId { get; set; }

    public string Name { get; set; }

    [ForeignKey("CompanyId")]
    public virtual CompanyDemographic Demographic { get; set; }

    public virtual ICollection<Contact> Contacts { get; set; }
}

public class CompanyDemographic
{
    [Key]
    [ForeignKey("Company")]
    public int CompanyId { get; set; }
    public virtual Company Company { get; set; }

    public int EmployeeCount { get; set; }
}

迁移正确构建，一切正常。

然后我将CompanyDemographic的引用添加回公司，如下所示：

public class CompanyDemographic
{
    [Key]
    [ForeignKey("Company")]
    public int CompanyId { get; set; }
    public virtual Company Company { get; set; }

    public int EmployeeCount { get; set; }

    // ADDING THIS
    [ForeignKey("CurrentProvider")]
    public int CurrentProviderCompanyId { get; set; }
    public virtual Company CurrentProvider { get; set; }
}

当我去添加迁移时，它看起来像这样：

public override void Up()
{
    DropForeignKey("dbo.Contacts", "CompanyId", "dbo.Companies");
    DropForeignKey("dbo.CompanyDemographics", "CompanyId", "dbo.Companies");
    DropPrimaryKey("dbo.Companies");
    AddColumn("dbo.CompanyDemographics", "CurrentProviderCompanyId", c => c.Int(nullable: false));
    AlterColumn("dbo.Companies", "CompanyId", c => c.Int(nullable: false));
    AddPrimaryKey("dbo.Companies", "CompanyId");
    CreateIndex("dbo.Companies", "CompanyId");
    CreateIndex("dbo.CompanyDemographics", "CurrentProviderCompanyId");
    AddForeignKey("dbo.CompanyDemographics", "CurrentProviderCompanyId", "dbo.Companies", "CompanyId", cascadeDelete: true);
    AddForeignKey("dbo.Contacts", "CompanyId", "dbo.Companies", "CompanyId", cascadeDelete: true);
    AddForeignKey("dbo.CompanyDemographics", "CompanyId", "dbo.Companies", "CompanyId");
}

它试图删除所有密钥并重建。我该如何避免这种情况？

Answer 1

将@Steve Greene评论转换为答案：

将[InverseAttribute（＆＃34; Company＆＃34;）]放在公司的人口统计属性（而不是ForeignKey）上解决了它！

[InverseAttribute("Company")]
public virtual CompanyDemographic Demographic { get; set; }

首先在相关表引用时一对一地发生EF迁移问题

1 个答案: