EF 核心外键配置问题

Question

我正在努力将实际的办公项目迁移到实体框架核心和.NET Core。 当我想进行添加迁移时，我卡住了。导航属性和外键似乎配置不正确。经过多次尝试，我无法解决我的问题。

添加迁移时出现错误消息：

The relationship from 'PlanLang.Plan' to 'Plan.Lang' with foreign key properties {'PlanId' : int} cannot target the primary key {'GolfClubId' : int, 'PlanId' : int} because it is not compatible. Configure a principal key or a set of compatible foreign key properties for this relationship.

这是我的实体：

高尔夫俱乐部

public class GolfClub
{
public int Id { get; set; }
//.. other properties, not important
}

计划

public class Plan
{
public int GolfClubId { get; set; }
public int PlanId { get; set; }
//.. other properties, not important
public GolfClub GolfClub { get; set; }
public ICollection<PlanLang> Lang { get; set; }
}

普朗

朗

public class PlanLang
{
public int GolfClubId { get;set; }
public int PlanId { get; set; }
public string Lang { get; set; }
//.. other properties, not important
public GolfClub GolfClub { get; set; }
public Plan Plan { get; set; }
}

这是我的配置：

public class GolfClubConfiguration : IEntityTypeConfiguration<GolfClub>
{
public void Configure(EntityTypeBuilder<GolfClub> builder)
{
builder.ToTable("gc_master");
builder.HasKey(k => new { k.Id });
builder.Property(p => p.Id).ValueGeneratedNever(); // to disable auto-increment
}
}
public class PlanConfiguration : IEntityTypeConfiguration<Plan>
{
public void Configure(EntityTypeBuilder<Plan> builder)
{
builder.ToTable("gc_plan_master");
builder.HasKey(k => new { k.GolfClubId, k.PlanId });
builder.Property(p => p.GolfClubId).ValueGeneratedNever(); // to disable auto-increment
builder.HasMany(p => p.Lang).WithOne(p => p.Plan).HasForeignKey(FK => FK.PlanId);
builder.HasOne(p => p.GolfClub).WithMany().HasForeignKey(FK => FK.GolfClubId);
}
}
public class PlanLangConfiguration : IEntityTypeConfiguration<PlanLang>
{
public void Configure(EntityTypeBuilder<PlanLang> builder)
{
builder.ToTable("gc_plan_master_lang");
builder.HasKey(k => new { k.GolfClubId, k.PlanId, k.Lang });
builder.Property(p => p.GolfClubId).ValueGeneratedNever(); // to disable auto-increment
builder.Property(p => p.Lang).HasMaxLength(5);
builder.HasOne(p => p.GolfClub).WithMany().HasForeignKey(FK => FK.GolfClubId);
}
}

我想要的是 Plan 有 1 个外键(GolfClubId)和 PlanLang 2 个外键(PlanId 和 GolfClubId)。

我可以通过哪种方式进行？

感谢您的回复。

Answer 1

问题出在PlanLang的GolfClubId。您的Plan有列表PlanLang和GolfClubId，其中单个PlanLang具有GolfClubId没有意义，这就是 EF Core 无法配置/确定关系的原因。

从PlanLang中删除GolfClubId，因为PlanLang已经通过Plan与GlofClub相关，以防PlanGolfClubId。

按如下所示编写模型类：

public class GolfClub
{
public int Id { get; set; }
//.. other properties, not important
}
public class Plan
{
public int PlanId { get; set; }
public int GolfClubId { get; set; }
//.. other properties, not important
public GolfClub GolfClub { get; set; }
public ICollection<PlanLang> PanLangs { get; set; }
}
public class PlanLang
{
public int PlanId { get; set; }
public string Lang { get; set; }
//.. other properties, not important
public Plan Plan { get; set; }
}

并按如下方式重写Plan和PlanLangEntityConfigurations：

public class PlanConfiguration : IEntityTypeConfiguration<Plan>
{
public void Configure(EntityTypeBuilder<Plan> builder)
{
builder.ToTable("gc_plan_master");
builder.HasKey(k => k.PlanId);
builder.HasMany(p => p.PlanLangs).WithOne(p => p.Plan).HasForeignKey(FK => FK.PlanId);
builder.HasOne(p => p.GolfClub).WithMany().HasForeignKey(FK => FK.GolfClubId);
}
}
public class PlanLangConfiguration : IEntityTypeConfiguration<PlanLang>
{
public void Configure(EntityTypeBuilder<PlanLang> builder)
{
builder.ToTable("gc_plan_master_lang");
builder.HasKey(k => new { k.PlanId, k.Lang });
builder.Property(p => p.Lang).HasMaxLength(5);
builder.HasOne(p => p.Plan).WithMany().HasForeignKey(FK => FK.PlanId);
}
}

现在一切应该正常了！