Entity framework 流畅映射多对多

Question

我在尝试映射此模型时遇到问题：

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;}
}

映射代码：

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);

    }
}

我遇到了这个错误：

在模型生成过程中检测到一个或多个验证错误：要求：FromRole：NavigationProperty 'Requirements' 无效。 AssociationType 'Discipline_Requirements' 中 FromRole 'Discipline_Requirements_Target' 的类型 'DisciplineRequeriment' 必须与声明此 NavigationProperty 的类型 'Discipline' 完全匹配。

有人可以给我点灯吗？

Answer 1

恕我直言，你必须有两个导航属性（或者至少如果只有一个你不能用两个 FK 配置它）

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;}
}

和

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);

    }
}

应该够了。

Entity framework 流畅映射多对多

Entity framework fluent mapping many-to-may

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many-to-many

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