使用 EFCore 为一对一关系生成迁移时出错

Question

我有两个型号如下：

public class Person{

   public virtual int Id { get; set; }
   public virtual int BaseId { get; set; }
   public virtual string Name { get; set; }
   public virtual Employee Employee { get; set; }
}

public class Employee{

   public virtual int Id { get; set; }
   public virtual string Code{ get; set; }
   public virtual Person Person { get; set; }
}

每个 Employee 都是一个 Person，但每个 Person 不一定是一个 Employee。这两者之间的关系是一对一关系类型，但我需要在非主键列（Person.BaseId）和所需的外键列（Employee.Id）之间建立这种关系。在面对Employee模型中的Id列同时是主键和外键列。

我有这个映射配置：

 public override void Configure(EntityTypeBuilder<Person> builder)
    {
        builder.HasKey(x => x.Id);
        builder.ToTable("tblPeople", "dbo");

        builder
            .HasOne(p => p.Employee)
            .WithOne(p => p.Person)
            .HasForeignKey<Employee>(p => p.Id)
            .HasPrincipalKey<Person>(p => p.BaseId);
    } 

  public override void Configure(EntityTypeBuilder<Employee> builder)
    {
        builder.HasKey(x => x.Id);
        builder.ToTable("tblEmployees", "dbo");
    }

当我尝试生成迁移时出现以下错误：

The child/dependent side could not be determined for the one-to-one relationship between 'Employee.Person' and 'Person.Employee'. To identify the child/dependent side of the relationship, configure the foreign key property. If these navigations should not be part of the same relationship configure them without specifying the inverse. See http://go.microsoft.com/fwlink/?LinkId=724062 for more details.

我不想使用数据注释方法来解决这个问题。

Answer 1

我找到了解决方案，错误出在我的 EntityTypeConfiguration classes 设计中。我有以下设计： 为简单起见，我裁剪了代码

public abstract class BaseMap<T, U> : IEntityTypeConfiguration<T> where T: BaseEntity<U>
{
    public virtual void Configure(EntityTypeBuilder<T> builder)
    {
        builder.HasKey(x => x.Id);
    }
}

public abstract class ChildBaseMap<T, U> : BaseMap<T, U> where T: ChildBaseEntity<U>
{
    public virtual void Configure(EntityTypeBuilder<T> builder)//<== virtual is wrong here as I need to override the parent Configure
    {
        base.Configure(builder);

        builder.Property(x => x.BaseId).IsRequired();
    }
}

public class PersonMap : ChildBaseMap<Person, int>
{
    public override void Configure(EntityTypeBuilder<Person> builder)
    {
      ....

只需override Configure 方法，而不是在ChildBaseMap 中将其定义为virtual class 解决问题！[=15=]

使用 EFCore 为一对一关系生成迁移时出错

Error while generating migration for One to One relation using EFCore

c#

entity-framework

one-to-one

ef-fluent-api

ef-core-2.0