實體框架流暢映射可能

Question

嘗試映射此模型時出現問題：

public class Discipline
{
    public int Id {get;set;}
    public string Name{get;set;}
    public virtual ICollection<DisciplineRequirement> Requirements {get;set;}
}

public class DisciplineRequirement
{
    public int DisciplineId {get;set;}
    public int RequiredDiscipline {get;set;}
    public virtual Discipline Discipline {get;set;}
    public virtual Discipline RequiredDiscipline {get;set;}
}

映射代碼：

public class DisciplineMap : EntityTypeConfiguration<Discipline>
{
    public DisciplineMap()
    {
        ToTable("Discipline");

        HasKey(p => p.Id);

        HasMany(p => p.Requirements)
            .WithRequired(p => p.Discipline)
            .HasForeignKey(p => p.DisciplineId);

        HasMany(p => p.Requirements)
            .WithRequired(p => p.RequiredDiscipline)
            .HasForeignKey(p => p.RequiredDisciplineId);
    }
}

public class DisciplineRequirementMap : EntityTypeConfiguration<DisciplineRequeriment>
{
    public DisciplineRequirementMap()
    {
        ToTable("DisciplineRequirement");

        HasKey(p => new
        {
            p.DisciplineId,
            p.RequiredDisciplineId
        });

        HasRequired(p => p.Discipline)
            .WithMany(p => p.Requirements)
            .HasForeignKey(p => p.DisciplineId);

        HasRequired(p => p.RequiredDiscipline)
            .WithMany(p => p.Requirements)
            .HasForeignKey(p => p.RequiredDisciplineId);

    }
}

我有這個錯誤：

在模型生成期間檢測到一個或多個驗證錯誤：要求：FromRole：NavigationProperty“要求”無效。 關聯類型'Discipline_Requirements'中FromRole'Discipline_Requirements_Target'的類型'DisciplineRequeriment'必須與聲明了該NavigationProperty的類型'Discipline'完全匹配。

有人可以在這里給我個燈嗎？

Answer 1

恕我直言，您必須具有兩個導航屬性（或者至少如果只有一個，則無法使用兩個FK對其進行配置）

public class Discipline
{
    public int Id {get;set;}
    public string Name{get;set;}
    public virtual ICollection<DisciplineRequirement> Requirements {get;set;}
    public virtual ICollection<DisciplineRequirement> RequiredBy {get;set;}
}

public class DisciplineRequirement
{
    public int DisciplineId {get;set;}
    public int RequiredDisciplineId {get;set;}
    public virtual Discipline Discipline {get;set;}
    public virtual Discipline RequiredDiscipline {get;set;}
}

同

public class DisciplineMap : EntityTypeConfiguration<Discipline>
{
    public DisciplineMap()
    {
        ToTable("Discipline");

        HasKey(p => p.Id);
    }
}

public class DisciplineRequirementMap : EntityTypeConfiguration<DisciplineRequeriment>
{
    public DisciplineRequirementMap()
    {
        ToTable("DisciplineRequirement");

        HasKey(p => new
        {
            p.DisciplineId,
            p.RequiredDisciplineId
        });

        HasRequired(p => p.Discipline)
            .WithMany(p => p.RequiredBy)
            .HasForeignKey(p => p.DisciplineId);

        HasRequired(p => p.RequiredDiscipline)
            .WithMany(p => p.Requirements)
            .HasForeignKey(p => p.RequiredDisciplineId);

    }
}

應該足夠了。