一个或多个实体的验证失败。有关更多详细信息，请参见“ EntityValidationErrors”属性

小编典典

一个或多个实体的验证失败。有关更多详细信息，请参见“ EntityValidationErrors”属性

使用代码优先方法为数据库播种时出现此错误。

一个或多个实体的验证失败。有关更多详细信息，请参见’EntityValidationErrors’属性。

老实说，我不知道如何检查验证错误的内容。Visual Studio向我展示了这是一个包含8个对象的数组，因此出现8个验证错误。

这适用于我以前的模型，但是做了一些更改，下面解释：

我有一个名为Status的枚举，我将其更改为一个名为Status的类
我将类ApplicantsPositionHistory更改为在同一张表中有2个外键

对冗长的代码，请原谅，但我必须全部粘贴。在以下代码的最后一行中引发异常。

namespace Data.Model
{  
    public class Position
    {
        [DatabaseGenerated(System.ComponentModel.DataAnnotations.DatabaseGeneratedOption.Identity)]   
        public int PositionID { get; set; }

        [Required(ErrorMessage = "Position name is required.")]
        [StringLength(20, MinimumLength = 3, ErrorMessage = "Name should not be longer than 20 characters.")]
        [Display(Name = "Position name")]              
        public string name { get; set; }

        [Required(ErrorMessage = "Number of years is required")] 
        [Display(Name = "Number of years")]        
        public int yearsExperienceRequired { get; set; }

        public virtual ICollection<ApplicantPosition> applicantPosition { get; set; }
    }

    public class Applicant
    {
        [DatabaseGenerated(System.ComponentModel.DataAnnotations.DatabaseGeneratedOption.Identity)]      
        public int ApplicantID { get; set; }

        [Required(ErrorMessage = "Name is required")] 
        [StringLength(20, MinimumLength = 3, ErrorMessage="Name should not be longer than 20 characters.")]
        [Display(Name = "First and LastName")]
        public string name { get; set; }

        [Required(ErrorMessage = "Telephone number is required")] 
        [StringLength(10, MinimumLength = 3, ErrorMessage = "Telephone should not be longer than 20 characters.")]
        [Display(Name = "Telephone Number")]
        public string telephone { get; set; }

        [Required(ErrorMessage = "Skype username is required")] 
        [StringLength(10, MinimumLength = 3, ErrorMessage = "Skype user should not be longer than 20 characters.")]
        [Display(Name = "Skype Username")]
        public string skypeuser { get; set; }

        public byte[] photo { get; set; }

        public virtual ICollection<ApplicantPosition> applicantPosition { get; set; }
    }

    public class ApplicantPosition
    {
        [Key]
        [Column("ApplicantID", Order = 0)]
        public int ApplicantID { get; set; }

        [Key]
        [Column("PositionID", Order = 1)]
        public int PositionID { get; set; }

        public virtual Position Position { get; set; }

        public virtual Applicant Applicant { get; set; }

        [Required(ErrorMessage = "Applied date is required")] 
        [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)]
        [Display(Name = "Date applied")]     
        public DateTime appliedDate { get; set; }

        [Column("StatusID", Order = 0)]
        public int StatusID { get; set; }

        public Status CurrentStatus { get; set; }

        //[NotMapped]
        //public int numberOfApplicantsApplied
        //{
        //    get
        //    {
        //        int query =
        //             (from ap in Position
        //              where ap.Status == (int)Status.Applied
        //              select ap
        //                  ).Count();
        //        return query;
        //    }
        //}
    }

    public class Address
    {
        [StringLength(20, MinimumLength = 3, ErrorMessage = "Country should not be longer than 20 characters.")]
        public string Country { get; set; }

        [StringLength(20, MinimumLength = 3, ErrorMessage = "City  should not be longer than 20 characters.")]
        public string City { get; set; }

        [StringLength(50, MinimumLength = 3, ErrorMessage = "Address  should not be longer than 50 characters.")]
        [Display(Name = "Address Line 1")]     
        public string AddressLine1 { get; set; }

        [Display(Name = "Address Line 2")]
        public string AddressLine2 { get; set; }   
    }

    public class ApplicationPositionHistory
    {
        [DatabaseGenerated(System.ComponentModel.DataAnnotations.DatabaseGeneratedOption.Identity)]
        public int ApplicationPositionHistoryID { get; set; }

        public ApplicantPosition applicantPosition { get; set; }

        [Column("oldStatusID")]
        public int oldStatusID { get; set; }

        [Column("newStatusID")]
        public int newStatusID { get; set; }

        public Status oldStatus { get; set; }

        public Status newStatus { get; set; }

        [StringLength(500, MinimumLength = 3, ErrorMessage = "Comments  should not be longer than 500 characters.")]
        [Display(Name = "Comments")]
        public string comments { get; set; }

        [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)]
        [Display(Name = "Date")]     
        public DateTime dateModified { get; set; }
    }

    public class Status
    {
        [DatabaseGenerated(System.ComponentModel.DataAnnotations.DatabaseGeneratedOption.Identity)]
        public int StatusID { get; set; }

        [StringLength(20, MinimumLength = 3, ErrorMessage = "Status  should not be longer than 20 characters.")]
        [Display(Name = "Status")]
        public string status { get; set; }
    }
}



using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Entity;
using System.IO;

namespace Data.Model
{
    public class HRContextInitializer : DropCreateDatabaseAlways<HRContext>
    {
        protected override void Seed(HRContext context)
        {
            #region Status
            Status applied = new Status() { status = "Applied" };
            Status reviewedByHR = new Status() { status = "Reviewed By HR" };
            Status approvedByHR = new Status() { status = "Approved by HR" };
            Status rejectedByHR = new Status() { status = "Rejected by HR" };
            Status assignedToTechnicalDepartment = new Status() { status = "Assigned to Technical Department" };
            Status approvedByTechnicalDepartment = new Status() { status = "Approved by Technical Department" };
            Status rejectedByTechnicalDepartment = new Status() { status = "Rejected by Technical Department" };

            Status assignedToGeneralManager = new Status() { status = "Assigned to General Manager" };
            Status approvedByGeneralManager = new Status() { status = "Approved by General Manager" };
            Status rejectedByGeneralManager = new Status() { status = "Rejected by General Manager" };

            context.Status.Add(applied);
            context.Status.Add(reviewedByHR);
            context.Status.Add(approvedByHR);
            context.Status.Add(rejectedByHR);
            context.Status.Add(assignedToTechnicalDepartment);
            context.Status.Add(approvedByTechnicalDepartment);
            context.Status.Add(rejectedByTechnicalDepartment);
            context.Status.Add(assignedToGeneralManager);
            context.Status.Add(approvedByGeneralManager);
            context.Status.Add(rejectedByGeneralManager); 
            #endregion

            #region Position
            Position netdeveloper = new Position() { name = ".net developer", yearsExperienceRequired = 5 };
            Position javadeveloper = new Position() { name = "java developer", yearsExperienceRequired = 5 };
            context.Positions.Add(netdeveloper);
            context.Positions.Add(javadeveloper); 
            #endregion

            #region Applicants
            Applicant luis = new Applicant()
            {
                name = "Luis",
                skypeuser = "le.valencia",
                telephone = "0491732825",
                photo = File.ReadAllBytes(@"C:\Users\LUIS.SIMBIOS\Documents\Visual Studio 2010\Projects\SlnHR\HRRazorForms\Content\pictures\1.jpg")
            };

            Applicant john = new Applicant()
            {
                name = "John",
                skypeuser = "jo.valencia",
                telephone = "3435343543",
                photo = File.ReadAllBytes(@"C:\Users\LUIS.SIMBIOS\Documents\Visual Studio 2010\Projects\SlnHR\HRRazorForms\Content\pictures\2.jpg")
            };

            context.Applicants.Add(luis);
            context.Applicants.Add(john); 
            #endregion

            #region ApplicantsPositions
            ApplicantPosition appicantposition = new ApplicantPosition()
            {
                Applicant = luis,
                Position = netdeveloper,
                appliedDate = DateTime.Today,
                StatusID = 1
            };

            ApplicantPosition appicantposition2 = new ApplicantPosition()
            {
                Applicant = john,
                Position = javadeveloper,
                appliedDate = DateTime.Today,
                StatusID = 1
            };

            context.ApplicantsPositions.Add(appicantposition);            
            context.ApplicantsPositions.Add(appicantposition2); 
            #endregion

            context.SaveChanges(); --->> Error here
        }
    }
}

阅读 364

2020-05-19

共1个答案

小编典典

老实说，我不知道如何检查验证错误的内容。Visual Studio向我展示了这是一个包含8个对象的数组，因此出现8个验证错误。

实际上，如果在调试期间在Visual Studio中钻入该阵列，则应该看到错误。但是您也可以捕获异常，然后将错误写出到某些日志存储区或控制台中：

try
{
    // Your code...
    // Could also be before try if you know the exception occurs in SaveChanges

    context.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;
}

EntityValidationErrors是表示无法成功验证的ValidationErrors实体的集合，每个实体的内部集合是属性级别的错误列表。

这些验证消息通常足以找到问题的根源。

编辑

一些小改进：

违规属性的值可以包含在内循环中，如下所示：

        foreach (var ve in eve.ValidationErrors)
        {
            Console.WriteLine("- Property: \"{0}\", Value: \"{1}\", Error: \"{2}\"",
                ve.PropertyName,
                eve.Entry.CurrentValues.GetValue<object>(ve.PropertyName),
                ve.ErrorMessage);
        }

尽管调试Debug.Write可能比Console.WriteLine其更适用，因为它可以在所有类型的应用程序中使用，而不仅仅是控制台应用程序（感谢@Bart在下面的评论中提供他的注释）。

对于在生产中并且使用 Elmah
进行异常日志记录的Web应用程序，事实证明，这对于我创建自定义异常并进行覆盖SaveChanges以抛出此新异常非常有用。

自定义异常类型如下所示：

public class FormattedDbEntityValidationException : Exception
{
    public FormattedDbEntityValidationException(DbEntityValidationException innerException) :
        base(null, innerException)
    {
    }

    public override string Message
    {
        get
        {
            var innerException = InnerException as DbEntityValidationException;
            if (innerException != null)
            {
                StringBuilder sb = new StringBuilder();

                sb.AppendLine();
                sb.AppendLine();
                foreach (var eve in innerException.EntityValidationErrors)
                {
                    sb.AppendLine(string.Format("- Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
                        eve.Entry.Entity.GetType().FullName, eve.Entry.State));
                    foreach (var ve in eve.ValidationErrors)
                    {
                        sb.AppendLine(string.Format("-- Property: \"{0}\", Value: \"{1}\", Error: \"{2}\"",
                            ve.PropertyName,
                            eve.Entry.CurrentValues.GetValue<object>(ve.PropertyName),
                            ve.ErrorMessage));
                    }
                }
                sb.AppendLine();

                return sb.ToString();
            }

            return base.Message;
        }
    }
}

并且SaveChanges可以通过以下方式覆盖：

public class MyContext : DbContext
{
    // ...

    public override int SaveChanges()
    {
        try
        {
            return base.SaveChanges();
        }
        catch (DbEntityValidationException e)
        {
            var newException = new FormattedDbEntityValidationException(e);
            throw newException;
        }
    }
}

几点评论：

Elmah在Web界面或已发送的电子邮件（如果已配置）中显示的黄色错误屏幕现在直接在消息顶部显示验证详细信息。
Message在自定义异常中覆盖而不是覆盖属性ToString()的好处是，标准ASP.NET“死亡黄屏（YSOD）”也显示此消息。与Elmah相反，YSOD显然不使用ToString()，但是两者都显示Message属性。
将原始文件包装DbEntityValidationException为内部异常可确保原始堆栈跟踪仍然可用，并显示在Elmah和YSOD中。
通过在行上设置一个断点，throw newException;您可以简单地将newException.Message属性作为文本进行检查，而不必钻研验证集合，这有点尴尬，而且似乎并不适合所有人（请参见下面的评论）。

2020-05-19