外键 C# MVC 5？

Question

我想将一个字符串字段关联为外键，我需要帮助！

catalogtype.code => catalog.typeCatalogRefCode

public class CatalogType : AuditFields
{
    [Key]
    public int id { get; set; }
    public string name { get; set; }
    public string description { get; set; }
    public string code { get; set; }
    public bool passive { get; set; }
    public ICollection<Catalog> Catalogs { get; set; }

}

public class Catalog : AuditFields
{
    [Key]
    public int id { get; set; }
    public string value { get; set; }
    public string description { get; set; }
    public string code { get; set; }
    public bool passive { get; set; }
    public int order { get; set; }
    public string typeCatalogRefCode { get; set; }
    public virtual CatalogType catalogType { get; set; }
}

.................................................. …………

public class AuditFields
{
    public DateTime createdDate { get; set; }
    public string createdBy { get; set; }
    public string createdIn { get; set; }
    public DateTime modifiedDate { get; set; }
    public string modifiedBy { get; set; }
    public string modifiedIn { get; set; }
}

Answer 1

请参考以下类结构。要将“typeCatalogRefCode”作为外键，您需要将“code”定义为键

class MyDBContext:DbContext
{
    public MyDBContext()
        : base("mydbcontext")
    {

    }
    static MyDBContext()
{
    Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyDBContext>());
}

public DbSet<CatalogType> CatalogTypes{ get; set; }
public DbSet<Catalog> Catalogs{ get; set; }
}
public class CatalogType : AuditFields
{

    public int id { get; set; }
    public string name { get; set; }
    public string description { get; set; }
            [Key]
    public string code { get; set; }
    public bool passive { get; set; }
    public ICollection<Catalog> Catalogs { get; set; }

}

public class Catalog : AuditFields
{
    [Key]
    public int id { get; set; }
    public string value { get; set; }
    public string description { get; set; }
    public string code { get; set; }
    public bool passive { get; set; }
    public int order { get; set; }
    public string typeCatalogRefCode { get; set; }
      [ForeignKey("typeCatalogRefCode")]
    public virtual CatalogType catalogType { get; set; }
}
public class AuditFields
{
    public DateTime createdDate { get; set; }
    public string createdBy { get; set; }
    public string createdIn { get; set; }
    public DateTime modifiedDate { get; set; }
    public string modifiedBy { get; set; }
    public string modifiedIn { get; set; }
}

Answer 2

您好，您需要在 dbcontext 类的覆盖方法 OnModelCreating 上编写代码。请参考以下代码。

public class CatalogContext : DbContext
{
    static CatalogContext()
    {
        Database.SetInitializer(new DropCreateDatabaseIfModelChanges<CatalogContext>());
    }
    public DbSet<CatalogType> CatalogTypes{ get; set; }
    public DbSet<Catalog> Catalogs{ get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelbuilder.Entity<Catalog>().HasOptional(a=>a.catalogType)
                            .WithMany(au=>au.Catalogs)
                            .HasForeignKey(a=>typeCatalogRefCode);
    }
}

Answer 3

Koderzzzz 的答案是正确的，但只是为了完成你也可以使用数据注释：

public class CatalogType : AuditFields
{
    [Key]
    public int id { get; set; }
    public string name { get; set; }
    public string description { get; set; }
    public string code { get; set; }
    public bool passive { get; set; }
    [InverseProperty("catalogType")]
    public ICollection<Catalog> Catalogs { get; set; }

}

public class Catalog : AuditFields
{
    [Key]
    public int id { get; set; }
    public string value { get; set; }
    public string description { get; set; }
    public string code { get; set; }
    public bool passive { get; set; }
    public int order { get; set; }
    public string typeCatalogRefCode { get; set; }
    [ForeignKey("typeCatalogRefCode")]
    public virtual CatalogType catalogType { get; set; }
}