违反PRIMARY KEY约束在MVC中插入项时出错

Question

这是我的班级

public class SmartPhone : BaseEntity
{
    [MaxLength(50, ErrorMessage = "Maximum length 50 character"), MinLength(1, ErrorMessage = "Min length 1 character")]
    public string Name { get; set; }
    public decimal Price { get; set; }
    public virtual Manufacture Manufacture { get; set; }
}   

此类具有Manufacture的外键。我用EF

public class Manufacture : BaseEntity
{
    [Required]
    [MaxLength(50, ErrorMessage = "The Manufacture Name must be a string and max length 50")]
    public string ManufactureName { get; set; }
    public virtual ICollection<SmartPhone> SmartPhones { get; set; }
}

当我使用mapper到我的DTo对象时

var mapper1 = Mapper.CreateMap<SmartPhoneDto, SmartPhone>();
mapper1.ForMember(d => d.Manufacture, s => s.MapFrom(a => a.ManufactureDto));

var mapper = Mapper.CreateMap<SmartPhone, SmartPhoneDto>();
mapper.ForMember(d => d.ManufactureDto, s => s.MapFrom(a => a.Manufacture));

当我调入SaveChanges时，插入我的数据库时会崩溃：

  

违反PRIMARY KEY约束'PK_dbo.Manufactures'。无法在对象'dbo.Manufactures'中插入重复键。

请帮我解决一下