
[英]Entity Framework, code-first, how to add primary key to table out of many-to-many relationship mapping?
[英]Entity Framework - Code first - One to Many relationship with shared primary key
任何人都知道如何使用EF Code First Fluent API来实现此方案:
public class Referancial
{
// Identity
public int KeyID { get; set; }
public string Code { get; set; }
public virtual ICollection<Translation> Translations { get; set; }
}
public class Translation
{
// refer to Referancial.KeyID
public int KeyID { get; set; }
public int LanguageID { get; set; }
public string Label { get; set; }
}
感谢您的答复
尝试其他型号,我认为它会更适合您
public class Referancial
{
// Identity
public int KeyID { get; set; }
public string Code { get; set; }
public virtual ICollection<Translation> Translations { get; set; }
}
public class Translation
{
//Translation needs its own Key
public int ID { get; set; }
// reference directly the Referencial object instead of the ID
public Referencial Referencial { get; set; }
public int LanguageID { get; set; }
public string Label { get; set; }
}
配置模型
_modelBuilder.Entity<Referancial>().HasKey(r => r.KeyID);
_modelBuilder.Entity<Translation>().HasKey(t => t.ID);
_modelBuilder.Entity<Referancial>().HasMany(r => r.Translations).WithRequired(t => t.Referencial).WillCascadeOnDelete(true);
//关于模型创建:
受保护的重写void OnModelCreating(DbModelBuilder modelBuilder){
// Person
modelBuilder.Entity<Person>().HasKey(e => e.PersonID)
.ToTable("Persons")
.Property(e => e.PersonID)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
//Referancial
modelBuilder.Entity<Referancial>().HasKey(e => e.KeyID)
.ToTable("Referancials")
.Property(e => e.KeyID)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
//Translation
modelBuilder.Entity<Translation>().ToTable("Translations")
.HasKey(e => e.KeyID)
.Property(e => e.KeyID)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
modelBuilder.Entity<Referancial>()
.HasOptional(e=>e.Translations)
.WithMany()
.HasForeignKey(e => e.KeyID);
base.OnModelCreating(modelBuilder);
}
但这使我犯了一个错误:
在模型生成期间检测到一个或多个验证错误:
PersonSearch.Models.Referancial_Translations::多重性与关系“ Referancial_Translations”中的角色“ Referancial_Translations_Target”中的引用约束冲突。 因为从属角色中的所有属性都是不可为空的,所以主体角色的多重性必须为'1'。 Referancial_Translations_Source ::多重性在关系“ Referancial_Translations”中的角色“ Referancial_Translations_Source”中无效。 由于从属角色指的是关键属性,因此从属角色的多重性上限必须为“ 1”。
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