Question

我正在尝试更新表bu.LastReviewCreationDate = LastReviewCreationDate;中的一行，但此操作会生成DbEntityValidationException。

      public void UpdateLastReviewCreationDate(string idBusiness, DateTime LastReviewCreationDate,string urlSite) {

            DAL.Business bu;
            try {
                using (DBContext tpContext = new DBContext())
                {
                    bu = tpContext.business.Find(idBusiness, urlSite);
                    if (bu != null)
                    {
                        bu.LastReviewCreationDate = LastReviewCreationDate;
                        tpContext.SaveChanges();
                    }
                }
            }
            catch (DbEntityValidationException e)
            {
                foreach (var eve in e.EntityValidationErrors)
                {
                    Console.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
                        eve.Entry.Entity.GetType().Name, eve.Entry.State);
                    foreach (var ve in eve.ValidationErrors)
                    {
                        Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
                            ve.PropertyName, ve.ErrorMessage);
                    }
                }
                throw;
            }
        }

所以这就是我在调试器中得到的：

这意味着此表格是只读的，不允许编辑。但我从未将此表设置为只读，这真的很奇怪。这是此表的代码。

 public class Business
    {
        public Business()
        {
            LastReviewCreationDate = new DateTime();
        }

        [Key, Column(Order = 0)]
        public string Id { get; set; } 

        [Key, Column(Order = 1)]
        [ForeignKey("site")]
        public string SiteId { get; set; }

        public string UrlBusiness { get; set; }
        public DateTime LastReviewCreationDate { get; set; }

        [Required]
        public virtual Site site { get;set;}
        public virtual BusinessUser businessUser{get;set;}

    }

也许有人有想法？是否可以将IsReadOnly参数重置为false？

Answer 1

最后我自己解决了这个问题。这是我抓住的例外情况：

Property: location, Error: The site field is required.

因为我将字段的必需属性设置为site，所以每次我想更新此表时，即使不需要更改site的值，也总是需要给它一个值通过客户端代码。

＆＃13;

 public class Business
    {
        public Business()
        {
            LastReviewCreationDate = new DateTime();
        }

        [Key, Column(Order = 0)]
        public string Id { get; set; } 

        [Key, Column(Order = 1)]
        [ForeignKey("site")]
        public string SiteId { get; set; }

        public string UrlBusiness { get; set; }
        public DateTime LastReviewCreationDate { get; set; }

        [Required]
        public virtual Site site { get;set;}
        public virtual BusinessUser businessUser{get;set;}

    }

＆＃13;

所以我只需在bu.site = siteE;

之前添加tpContext.SaveChanges();即可解决此问题

＆＃13;

      public void UpdateLastReviewCreationDate(string idBusiness, DateTime LastReviewCreationDate,string urlSite) {

            DAL.Business bu;
            try {
                using (DBContext tpContext = new DBContext())
                {
                    bu = tpContext.business.Find(idBusiness, urlSite);
                    DAL.Site siteE = bu.site;
                    if (bu != null)
                    {
                        bu.LastReviewCreationDate = LastReviewCreationDate;
                        bu.site = siteE;
                        tpContext.SaveChanges();
                    }
                }
            }
            catch (DbEntityValidationException e)
            {
                foreach (var eve in e.EntityValidationErrors)
                {
                    Console.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
                        eve.Entry.Entity.GetType().Name, eve.Entry.State);
                    foreach (var ve in eve.ValidationErrors)
                    {
                        Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
                            ve.PropertyName, ve.ErrorMessage);
                    }
                }
                throw;
            }
        }

＆＃13;

希望这会有所帮助。

Answer 2

发生了某种数据库验证，阻止您将数据写入其中。实际上，如果在调试期间在Visual Studio中钻入该数组，则应该看到错误。但您也可以捕获异常，然后将错误写入某些日志存储或控制台：

当我尝试使用实体框架更新表中的行时获取DbEntityValidationException

2 个答案: