我的 [Column（TypeName=“varchar（10）”）] 不起作用

问：

我将属性设置为 to，但当我运行时它是 。benefitID[Column(TypeName="varchar(10)")]benefitnvarchar(450)

[Key]
[Column(TypeName="varchar(10)")]
[StringLength(20)]
[Required]
private string benefitID;
private string benefitContent;//nội dung quyền lợi
public virtual ICollection<Job> Jobs { get; set; }

public string BenefitID { get => benefitID; set => benefitID = value; }
public string BenefitContent { get => benefitContent; set => benefitContent = value; }

public Benefit() 
{
    Jobs = new HashSet<Job>();
}

我希望跑步时是.benefitvarchar(10)