EF核心：没有导航属性的多对多关系映射

Question

我正在尝试使用Fluent API在实体Framework Core中创建多对多关系这是我的第一个模型：

MyCalculationSelector.cs

  public int SortOrder { get; set; }
  public string UserString { get { return Name; } }

  private IList<CalculationType> _calculationTypes;
  public virtual IList<CalculationType> CalculationTypes
    {
       get { return _calculationTypes; }
       set { _calculationTypes = value; }
    }

这是我的第二个模特：

MyCalculationType.cs

 public int SortOrder { get; set; }

 public string UserString
 {
    get { return Name; }
 }

 public int CalculationMethod { get; set; }

[我记得EF 6可以很容易地通过Fluent API建立多对多关系：

modelBuilder.Entity<MyCalculationSelector>().HasMany(x => x.MyCalculationTypes).WithMany();

我们可以在ef core中实现这样的功能吗？截止到今天，Hasmany-Withmany的实施尚无法实现

Answer 1

我已经阅读了文档，并想出了这个答案，请比我了解更多的人，如果我错了，我会纠正我。

我首先创建了我的联接表：

CalculationSelectorCalculationType.cs

public class CalculationSelectorCalculationType
    {
        public int CalculationSelector_Id { get; set; }
        public CalculationSelector CalculationSelector { get; set; }

        public int CalculationType_Id { get; set; }
        public CalculationType CalculationType { get; set; }
    }

CalculationSelector.cs

public CalculationSelector()
   {
      _calculationTypes = new List<CalculationSelectorCalculationType>();
      FontSize = 30;
   }
public int SortOrder { get; set; }
public string UserString { get { return Name; } }

private IList<CalculationSelectorCalculationType> _calculationTypes;
public virtual IList<CalculationSelectorCalculationType> CalculationTypes
    {
       get { return _calculationTypes; }
       set { _calculationTypes = value; }
    }

CalculationType.cs

 public int SortOrder { get; set; }

 public string UserString
 {
    get { return Name; }
 }

 public int CalculationMethod { get; set; }

...最后是我的DbContext：

modelBuilder.Entity<CalculationSelectorCalculationType>().HasKey(p => new { p.CalculationSelector_Id, p.CalculationType_Id });
modelBuilder.Entity<CalculationSelectorCalculationType>().HasOne(p => p.CalculationSelector).WithMany(x => x.CalculationTypes).HasForeignKey(p => p.CalculationSelector_Id);
modelBuilder.Entity<CalculationSelectorCalculationType>().HasOne(p => p.CalculationType).WithMany().HasForeignKey(p => p.CalculationType_Id);