Question

嗨，我有一个模型类

    public class Individual : EntityBase
{
    public Individual()
    {
        RelatedIndividuals = new HashSet<RelatedIndividual>();
    }

    public string FirstName { get; set; }

    public string PersonalNumber { get; set; }

    public ICollection<RelatedIndividual> RelatedIndividuals { get; set; }


}

此个人将具有一些具有相关类型的相关个人，我希望在同一表中具有多对多连接，因此我创建了另一个类

    public class RelatedIndividual
{
    [Column("RelatedIndividualType")]
    public RelatedIndividualType RelatedIndividualType { get; set; }

    [Key, Column(Order = 0)]
    public long IndividualId { get; set; }

    [Key, Column(Order = 1)]
    public long RelatedIndividualId { get; set; }
}

我试图在我的contextDB中做

        protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Individual>()
            .HasMany(p => p.RelatedIndividuals)
            .WithMany()
            .Map(m =>
            {
                m.MapLeftKey("IndividualId");
                m.MapRightKey("RelatedIndividualId");
                m.ToTable("RelatedIndividual");
            });
    }

但是我在WithMany上出错

“严重性代码描述项目文件行抑制状态错误CS1061'CollectionNavigationBuilder'不包含'WithMany'的定义，并且找不到可以接受的扩展方法'WithMany'接受类型为'CollectionNavigationBuilder'的第一个参数（您是否缺少using指令或程序集引用？）存储库C： \ Users \ Luka \ Desktop \ Individuals \ Repositories \ Context \ IndividualsDbContext.cs 23活动 “

有什么建议吗？如何正确执行？

之后编辑：我尝试过

    public class Individual : EntityBase
{
    public Individual()
    {
        RelatedIndividuals = new HashSet<RelatedIndividual>();
        RelatedIndividualsOf = new HashSet<RelatedIndividual>();
    }

    [MaxLength(50),MinLength(2), Column(TypeName = "nvarchar(50)")]
    public string FirstName { get; set; }
    [MaxLength(50), MinLength(2), Column(TypeName = "nvarchar(50)")]
    public string LastName { get; set; }

    public ICollection<RelatedIndividual> RelatedIndividuals { get; set; }
    public ICollection<RelatedIndividual> RelatedIndividualsOf { get; set; }
}

和我的第二堂课

    public class RelatedIndividual
{
    [Column("RelatedIndividualType")]
    public RelatedIndividualType RelatedIndividualType { get; set; }

    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public long IndividualId { get; set; }

    [ForeignKey("IndividualId")]
    public Individual Individual { get; set; }

    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public long RelateIndividualId { get; set; }

    [ForeignKey("RelateIndividualId")]
    public Individual RelateIndividual { get; set; }
}

我的上下文如下

        protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<RelatedIndividual>()
.HasKey(e => new { e.IndividualId, e.RelateIndividualId });

        modelBuilder.Entity<RelatedIndividual>()
                   .HasOne(pt => pt.Individual)
                   .WithMany(p => p.RelatedIndividuals)
                   .HasForeignKey(pt => pt.IndividualId);

        modelBuilder.Entity<RelatedIndividual>()
            .HasOne(pt => pt.RelateIndividual)
            .WithMany(t => t.RelatedIndividualsOf)
            .HasForeignKey(pt => pt.RelateIndividualId)
            .OnDelete(DeleteBehavior.Restrict);
    }

当我创建自然人时，它可以正常工作，当我创建自然人时，在自然人中，我添加RelatedIndividual，Ids不匹配，并且它同时添加了RelatedIndividuals和relatedIndividualsOf，例如，如果我新创建的个人是Id 2和当基数保存时，我将他与ID 1相关请2、2而不是1、2帮助。

Answer 1

您如何将这些信息存储在单个数据库表中？

但是，即使可以-EF核心也不直接支持多对多关系。您需要定义联接表，以便您具有两个一对多关系。这就是数据库建模的工作方式。

EF 6确实隐式创建了一个联接表，但是幸运的是EF core没有创建

相同表多对多连接EF CodeFirst .net Core

1 个答案: