一个或多个实体的验证失败.有关详细信息,请参阅"EntityValidationErrors"属性

Question

我在使用代码优先方法播种数据库时遇到此错误.

一个或多个实体的验证失败.有关详细信息,请参阅"EntityValidationErrors"属性.

说实话,我不知道如何检查验证错误的内容.Visual Studio向我显示它是一个包含8个对象的数组,因此有8个验证错误.

这与我之前的模型有关,但我做了一些修改,我在下面解释:

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

请原谅我的长代码,但我必须将其全部粘贴.在以下代码的最后一行中抛出异常.

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
        }
    }
}

Answer 1

说实话,我不知道如何检查验证错误的内容.Visual Studio向我显示它是一个包含8个对象的数组,因此有8个验证错误.

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:

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是一个集合,表示无法成功验证的实体,ValidationErrors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:

有问题的属性的值可以包含在内部循环中,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);
        }

虽然调试Debug.Write可能比Console.WriteLine所有类型的应用程序更适合,但不仅仅适用于控制台应用程序(感谢@Bart在下面的评论中提供的注释).

对于正在生产并使用Elmah进行异常日志记录的Web应用程序,对我来说,创建自定义异常和覆盖SaveChanges以便抛出这个新异常非常有用.

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中显示的黄色错误屏幕(如果已配置)现在直接在邮件顶部显示验证详细信息.

• 覆盖Message自定义异常中的属性而不是覆盖ToString()具有标准ASP.NET"黄色死亡屏幕(YSOD)"也显示此消息的好处.与Elmah相比,YSOD显然没有使用ToString(),但两者都显示了Message属性.

• 将原始包装DbEntityValidationException作为内部异常包装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,而不是深入到验证集合中,这有点尴尬,似乎并不适合每个人(请参阅下面的注释).

Answer 2

您可以在调试期间从Visual Studio中执行此操作而无需编写任何代码,甚至不是catch块.

只需添加一个名称为的手表:

((System.Data.Entity.Validation.DbEntityValidationException)$exception).EntityValidationErrors

watch表达式$exception显示当前上下文中抛出的任何异常,即使它尚未被捕获并分配给变量.

基于http://mattrandle.me/viewing-entityvalidationerrors-in-visual-studio/

Answer 3

这实际上可以在不必编写代码的情况下完成:

在catch块中,在以下代码行中添加一个断点:

catch (Exception exception)
{

}

现在,如果您将鼠标悬停在exception其上或将其添加到其中Watch,然后导航到异常详细信息,如下所示; 您将看到哪个特定列导致问题,因为当违反表约束时通常会发生此错误.

大图

Answer 4

以下是如何,您可以检查的内容EntityValidationErrors期间在Visual Studio(而无需编写任何额外的代码),即调试的IDE.

问题？

你是对的,Visual Studio调试器的View Details Popup没有显示EntityValidationErrors集合中的实际错误.

解决方案!

只需在" 快速监视"窗口中添加以下表达式,然后单击" 重新评估".

((System.Data.Entity.Validation.DbEntityValidationException)$exception).EntityValidationErrors

就我而言,看看我如何能够扩展到集合ValidationErrors List内部EntityValidationErrors

参考文献: mattrandle.me博客文章,@ yoel的回答

Answer 5

要快速查看第一个错误而不添加手表,您可以将其粘贴到立即窗口中:

((System.Data.Entity.Validation.DbEntityValidationException)$exception)
    .EntityValidationErrors.First()
    .ValidationErrors.First()

Answer 6

对于任何工作的人 VB.NET

Try
Catch ex As DbEntityValidationException
    For Each a In ex.EntityValidationErrors
        For Each b In a.ValidationErrors
            Dim st1 As String = b.PropertyName
            Dim st2 As String = b.ErrorMessage
        Next
    Next
End Try

Answer 7

当您处于catch {...}块内的调试模式时,打开"QuickWatch"窗口(ctrl+ alt+ q)并粘贴到那里:

((System.Data.Entity.Validation.DbEntityValidationException)ex).EntityValidationErrors

要么:

((System.Data.Entity.Validation.DbEntityValidationException)$exception).EntityValidationErrors

如果您不在try/catch中,或者无法访问异常对象.

这将允许您深入到ValidationErrors树中.这是我发现能够即时了解这些错误的最简单方法.

Answer 8

如果您只是捕获一个通用异常,那么将它转换为DbEntityValidationException可能会让您受益.这种类型的异常具有Validation Errors属性,并且继续扩展您的方式,您将找到所有问题.

例如,如果在catch中放置一个断点,则可以将以下内容放入监视中:

((System.Data.Entity.Validation.DbEntityValidationException ) ex)

错误的一个示例是,如果某个字段不允许空值,并且您有一个空字符串,您会看到该字段是必需的.

Answer 9

在调试中,您可以在QuickWatch表达式评估程序输入字段中输入:

context.GetValidationErrors()

Answer 10

也在努力解决这个错误，并且根据此处的主题，这个答案能够找出要复制/粘贴的代码片段，而无需弄清楚必须导入的内容（对于 C# 初学者来说非常好），代码如下：

try
{
  context.SaveChanges();
}
catch (System.Data.Entity.Validation.DbEntityValidationException ex)
{
  foreach (var entityValidationErrors in ex.EntityValidationErrors)
  {
    foreach (var validationError in entityValidationErrors.ValidationErrors)
    {
      System.Diagnostics.Debug.WriteLine("Property: " + validationError.PropertyName + " Error: " + validationError.ErrorMessage);
    }
  }
}

Answer 11

只需检查数据库表字段长度.输入文本大于列字段数据类型长度

Answer 12

Per @ Slauma的答案和@Milton的建议我已经使用try/catch扩展了我们的基类的自定义保存方法,它将处理(并因此登录我们的错误记录!)这些异常.

// Where `BaseDB` is your Entities object... (it could be `this` in a different design)
public void Save(bool? validateEntities = null)
{
    try
    {
        //Capture and set the validation state if we decide to
        bool validateOnSaveEnabledStartState = BaseDB.Configuration.ValidateOnSaveEnabled;
        if (validateEntities.HasValue)
            BaseDB.Configuration.ValidateOnSaveEnabled = validateEntities.Value;

        BaseDB.SaveChanges();

        //Revert the validation state when done
        if (validateEntities.HasValue)
            BaseDB.Configuration.ValidateOnSaveEnabled = validateOnSaveEnabledStartState;
    }
    catch (DbEntityValidationException e)
    {
        StringBuilder sb = new StringBuilder();
        foreach (var eve in e.EntityValidationErrors)
        {
            sb.AppendLine(string.Format("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)
            {
                sb.AppendLine(string.Format("- Property: \"{0}\", Error: \"{1}\"",
                                            ve.PropertyName,
                                            ve.ErrorMessage));
            }
        }
        throw new DbEntityValidationException(sb.ToString(), e);
    }
}

Answer 13

我必须在立即窗口中写这个:3

(((exception as System.Data.Entity.Validation.DbEntityValidationException).EntityValidationErrors as System.Collections.Generic.List<System.Data.Entity.Validation.DbEntityValidationResult>)[0].ValidationErrors as System.Collections.Generic.List<System.Data.Entity.Validation.DbValidationError>)[0]

为了深入到确切的错误!

Answer 14

@Slauma的答案真的很棒但我发现当ComplexType属性无效时它不起作用.

例如,假设您拥有Phone复杂类型的属性PhoneNumber.如果AreaCode属性无效,则属性名称ve.PropertyNames为"Phone.AreaCode".这会导致调用eve.Entry.CurrentValues<object>(ve.PropertyName)失败.

要解决此问题,您可以在每个属性名称中拆分属性名称.,然后通过生成的属性名称数组进行递归.最后,当您到达链的底部时,您只需返回属性的值即可.

下面是@ Slauma的FormattedDbEntityValidationException类,支持ComplexTypes.

请享用!

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

    public override string Message
    {
        get
        {
            var innerException = InnerException as DbEntityValidationException;
            if (innerException == null) return base.Message;

            var 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)
                {
                    object value;
                    if (ve.PropertyName.Contains("."))
                    {
                        var propertyChain = ve.PropertyName.Split('.');
                        var complexProperty = eve.Entry.CurrentValues.GetValue<DbPropertyValues>(propertyChain.First());
                        value = GetComplexPropertyValue(complexProperty, propertyChain.Skip(1).ToArray());
                    }
                    else
                    {
                        value = eve.Entry.CurrentValues.GetValue<object>(ve.PropertyName);
                    }
                    sb.AppendLine(string.Format("-- Property: \"{0}\", Value: \"{1}\", Error: \"{2}\"",
                        ve.PropertyName,
                        value,
                        ve.ErrorMessage));
                }
            }
            sb.AppendLine();

            return sb.ToString();
        }
    }

    private static object GetComplexPropertyValue(DbPropertyValues propertyValues, string[] propertyChain)
    {
        var propertyName = propertyChain.First();
        return propertyChain.Count() == 1 
            ? propertyValues[propertyName] 
            : GetComplexPropertyValue((DbPropertyValues)propertyValues[propertyName], propertyChain.Skip(1).ToArray());
    }
}

Answer 15

请注意,它Entity.GetType().BaseType.Name给出了您指定的类型名称,而不是名称中包含所有十六进制数字的名称.

Answer 16

使用@Slauma的答案,我已经制作了一个代码片段(带有代码片段的环绕声),以便更好地使用.

<?xml version="1.0" encoding="utf-8"?>
<CodeSnippets xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
  <CodeSnippet Format="1.0.0">
    <Header>
      <SnippetTypes>
        <SnippetType>SurroundsWith</SnippetType>
      </SnippetTypes>
      <Title>ValidationErrorsTryCatch</Title>
      <Author>Phoenix</Author>
      <Description>
      </Description>
      <HelpUrl>
      </HelpUrl>
      <Shortcut>
      </Shortcut>
    </Header>
    <Snippet>
      <Code Language="csharp"><![CDATA[try
{
    $selected$ $end$
}
catch (System.Data.Entity.Validation.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;
}]]></Code>
    </Snippet>
  </CodeSnippet>
</CodeSnippets>

Answer 17

在try catch中捕获异常,然后快速监视或按Ctrl + d&ctrl + q,您可以深入查看EntityValidationErrors.

Answer 18

只是把我的两分钱丢进...

在我的dbConfiguration.cs中，我想将context.SaveChanges（）方法包装到try / catch中，并生成一个输出文本文件，该文件可让我清楚地读取错误，并且此代码也为它们添加了时间戳-如果您愿意，则很方便在不同的时间遇到​​多个错误！

        try
        {
            context.SaveChanges();
        }
        catch (DbEntityValidationException e)
        {
            //Create empty list to capture Validation error(s)
            var outputLines = new List<string>();

            foreach (var eve in e.EntityValidationErrors)
            {
                outputLines.Add(
                    $"{DateTime.Now}: Entity of type \"{eve.Entry.Entity.GetType().Name}\" in state \"{eve.Entry.State}\" has the following validation errors:");
                outputLines.AddRange(eve.ValidationErrors.Select(ve =>
                    $"- Property: \"{ve.PropertyName}\", Error: \"{ve.ErrorMessage}\""));
            }
            //Write to external file
            File.AppendAllLines(@"c:\temp\dbErrors.txt", outputLines);
            throw;
        }

Answer 19

我发现...当我收到“ EntityValidationErrors”错误时，....我在数据库“ db1”中的表“ tbladdress”中的字段为“ address1”，其大小为100（即地址varchar（100） null），并且我传递的值超过100个字符。这导致在将数据保存到数据库时出错。

因此，您必须检查要传递给该字段的数据。