EF代码第一：我如何看到从NuGet包控制台“EntityValidationErrors”属性？E

2019-05-12 21:46发布

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我在这一个损失：

我定义我的班了实体框架（4.1.3）代码第一种方法。一切都很好（我是创建表等），直到我开始播种。

现在，当我做

Add-Migration "remigrate" ; Update-Database;

我得到的包控制台上的错误“验证失败的一个或多个实体。请参阅‘EntityValidationErrors’属性的更多细节。”

我有一个断点在我的种子（）方法，但因为我运行这个项目不运行时在控制台上，我无能，如何才能到细节（PS -我见过的线程验证失败对一个或多个实体，而使用实体框架更改保存到SQL Server数据库，显示我怎么能看到的属性。）

我知道，因为如果我把返回的方法调用之后，错误消失我的种子（）方法有问题。那么，如何设置我的断点，这样我就可以看到验证错误是什么？有点丢失。或者是有一些其他的方式来跟踪它在控制台的NuGet？

Answer 1:

我被这样的事情困扰过最近。我固定它通过把一个包装函数在配置类种子的方法，并更换到调用SaveChanges通过调用我的函数。这个函数会简单地列举错误内EntityValidationErrors收集，并重新抛出在异常消息列出了个别问题的异常。这使得在NuGet包管理器控制台输出显示。

代码如下：

/// <summary>
/// Wrapper for SaveChanges adding the Validation Messages to the generated exception
/// </summary>
/// <param name="context">The context.</param>
private void SaveChanges(DbContext context) {
    try {
        context.SaveChanges();
    } catch (DbEntityValidationException ex) {
        StringBuilder sb = new StringBuilder();

        foreach (var failure in ex.EntityValidationErrors) {
            sb.AppendFormat("{0} failed validation\n", failure.Entry.Entity.GetType());
            foreach (var error in failure.ValidationErrors) {
                sb.AppendFormat("- {0} : {1}", error.PropertyName, error.ErrorMessage);
                sb.AppendLine();
            }
        }

        throw new DbEntityValidationException(
            "Entity Validation Failed - errors follow:\n" + 
            sb.ToString(), ex
        ); // Add the original exception as the innerException
    }
}

只需更换到调用context.SaveChanges()与SaveChanges(context)在种子的方法。

Answer 2:

已经扩展您的DbContext类与部分类定义！

如果你看一下类定义为您的DbContext这将是类似如下：

// DatabaseContext.cs   -- This file is auto generated and thus shouldn't be changed. 
public partial class [DatabaseContextName] : DbContext { ... }

因此，在另一个文件中，你可以创建相同的定义，并覆盖你想要的部分。

// partialDatabaseContext.cs  -- you can safely make changes 
// that will not be overwritten in here.
public partial class [DatabaseContextName] : DbContext { // Override defaults here }

与--did你注意到的DbContext部分类整体思路是部分分类-是你可以扩展已生成的类（或类组织成多个文件），并在我们的情况下，我们也希望覆盖 SaveChanges方法从该增加了的DbContext的局部类内。

这样，我们可以从错误调试信息的所有现有的DbContext /调用的SaveChanges无处不在，不必改变你的种子代码或开发代码。

这是我会做什么（注：不同的是，我只是覆盖SaveChanges方法在我们自己创作的DbContext部分类， 而不是所产生的一个 ）。此外，请确保你的部分类使用正确的命名空间 ，否则将靠墙敲打你的头。

public partial class Database : DbContext
{
    public override int SaveChanges()
    {
        try
        {
            return base.SaveChanges();
        }
        catch (DbEntityValidationException ex)
        {
            var sb = new StringBuilder();

            foreach (var failure in ex.EntityValidationErrors)
            {
                sb.AppendFormat("{0} failed validation\n", failure.Entry.Entity.GetType());
                foreach (var error in failure.ValidationErrors)
                {
                    sb.AppendFormat("- {0} : {1}", error.PropertyName, error.ErrorMessage);
                    sb.AppendLine();
                }
            }

            throw new DbEntityValidationException(
                "Entity Validation Failed - errors follow:\n" +
                sb.ToString(), ex
                ); // Add the original exception as the innerException
        }
    }
}

Answer 3:

我转换理查兹答案扩展方法：

  public static int SaveChangesWithErrors(this DbContext context)
    {
        try
        {
            return context.SaveChanges();
        }
        catch (DbEntityValidationException ex)
        {
            StringBuilder sb = new StringBuilder();

            foreach (var failure in ex.EntityValidationErrors)
            {
                sb.AppendFormat("{0} failed validation\n", failure.Entry.Entity.GetType());
                foreach (var error in failure.ValidationErrors)
                {
                    sb.AppendFormat("- {0} : {1}", error.PropertyName, error.ErrorMessage);
                    sb.AppendLine();
                }
            }

            throw new DbEntityValidationException(
                "Entity Validation Failed - errors follow:\n" +
                sb.ToString(), ex
            ); // Add the original exception as the innerException
        }
    }

这样调用：

context.SaveChangesWithErrors();

Answer 4:

我转换craigvl的版本，以C＃我不得不添加context.SaveChanges（）; 为了它为我工作如下。

try
{
    byte[] bytes = System.IO.File.ReadAllBytes(@"C:\Users\sheph_000\Desktop\Rawr.png");
    Console.WriteLine(bytes);

    context.BeverageTypes.AddOrUpdate(
        x => x.Name,
        new AATPos.DAL.Entities.BeverageType { ID = 1, Name = "Sodas" }
        );

    context.Beverages.AddOrUpdate(
        x => x.Name,
        new AATPos.DAL.Entities.Beverage { ID = 1, Name = "Coke", BeverageTypeID = 1, ImageData = bytes, IsStocked = true, StockLevel = 10, Price = 10.00M, ImageMimeType = "test" },
        new AATPos.DAL.Entities.Beverage { ID = 2, Name = "Fanta", BeverageTypeID = 1, ImageData = bytes, IsStocked = true, StockLevel = 10, Price = 10.00M, ImageMimeType = "test" },
        new AATPos.DAL.Entities.Beverage { ID = 3, Name = "Sprite", BeverageTypeID = 1, ImageData = bytes, IsStocked = true, StockLevel = 10, Price = 10.00M, ImageMimeType = "test" },
        new AATPos.DAL.Entities.Beverage { ID = 4, Name = "Cream Soda", BeverageTypeID = 1, ImageData = bytes, IsStocked = true, StockLevel = 10, Price = 10.00M, ImageMimeType = "test" },
        new AATPos.DAL.Entities.Beverage { ID = 5, Name = "Pepsi", BeverageTypeID = 1, ImageData = bytes, IsStocked = true, StockLevel = 10, Price = 10.00M, ImageMimeType = "test" }
        );

    context.SaveChanges();
}
catch (System.Data.Entity.Validation.DbEntityValidationException ex)
{
    var sb = new System.Text.StringBuilder();
    foreach (var failure in ex.EntityValidationErrors)
            {
                sb.AppendFormat("{0} failed validation", failure.Entry.Entity.GetType());
        foreach (var error in failure.ValidationErrors)
                {
            sb.AppendFormat("- {0} : {1}", error.PropertyName, error.ErrorMessage);
            sb.AppendLine();
                }
            }

    throw new Exception(sb.ToString());
}

Answer 5:

理查德感谢让我在正确的道路上（有同样的问题）下面是没有这个的迁移配置种子法为我工作的包装替代：

 Protected Overrides Sub Seed(context As NotificationContext)

        Try
            context.System.AddOrUpdate(
               Function(c) c.SystemName,
                New E_NotificationSystem() With {.SystemName = "System1"},
                New E_NotificationSystem() With {.SystemName = "System2"},
                New E_NotificationSystem() With {.SystemName = "System3"})

            context.SaveChanges()

        Catch ex As DbEntityValidationException

            Dim sb As New StringBuilder

            For Each failure In ex.EntityValidationErrors

                sb.AppendFormat("{0} failed validation" & vbLf, failure.Entry.Entity.[GetType]())

                For Each [error] In failure.ValidationErrors
                    sb.AppendFormat("- {0} : {1}", [error].PropertyName, [error].ErrorMessage)
                    sb.AppendLine()
                Next
            Next

            Throw New Exception(sb.ToString())

        End Try
End Sub

然后能看到包管理器控制台中的例外。希望这可以帮助别人。

Answer 6:

 I Also had same model validation problem but successfully catch by myself after lot of thinking; I use reverse engineering method to catch the problem out of Over 80 + Model Classes; 1> Made copy of dbcontext, changing the name (I add "1" at end and make respective changes in class constructor and initialization etc. Old: >public class AppDb : IdentityDbContext<ApplicationUser> > > { > public AppDb(): base("DefaultConnection", throwIfV1Schema: false) > { > > } > > public static AppDb Create() >{ >return new AppDb(); >} **New:** >public class AppDb1 : IdentityDbContext<ApplicationUser> >{ >public AppDb1() >: base("DefaultConnection", throwIfV1Schema: false) >{ >} > >public static AppDb1 Create() > { > return new AppDb1(); > }` ... 2> Make changes to Codefirst Migration Configuration from Old DbContext to my new Context. > internal sealed class Configuration : > DbMigrationsConfiguration<DAL.AppDb1> { public Configuration() { > AutomaticMigrationsEnabled = false; } protected override void > Seed(DAL.AppDb1 context) {` 3> Comment the Dbsets in new DbContext which was doubt. 4> Apply update migration if succeeded the probelm lye in Commented section. 5> if not then commented section is clear of bug clear. 6> repeat the (4) until found the right place of bug. 7> Happy Codding

文章来源: EF Code First: How do I see 'EntityValidationErrors' property from the nuget package console?