常用EF生成数据表字段属性

        //主键
        [Key]
        public Guid Id { get; set; }

        //自增主键 
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public Guid UserGuid { get; set; }


        //可空字段
        public Guid? TenantId { get; set; }

        //非空字段
        [Required]
        public int RechargeDays { get; set; }

        //固定类型
        [Column(TypeName ="datetime")]
        public System.DateTime RechargeTime { get; set; }

        //固定类型与长度
        [Column(TypeName ="nvarchar(200)")]
        public string Remark { get; set; }

        //最大 最小长度
        [MaxLength(30), MinLength(5)]
        public string CategoryName { get; set; }