如何解决使用实体框架将更改保存到SQL Server数据库时，一个或多个实体的验证失败
|| 我想将我的编辑保存到数据库，并且在ASP.NET MVC 3 / C＃中使用实体框架优先代码，但出现错误。在我的Event类中，我有DateTime和TimeSpan数据类型，但是在我的数据库中，我分别有Date和time。这可能是原因吗？将更改保存到数据库之前，如何在代码中强制转换为适当的数据类型。public class Event
{
public int EventId { get; set; }
public int CategoryId { get; set; }
public int PlaceId { get; set; }
public string Title { get; set; }
public decimal Price { get; set; }
public DateTime EventDate { get; set; }
public TimeSpan StartTime { get; set; }
public TimeSpan EndTime { get; set; }
public string Description { get; set; }
public string EventPlaceUrl { get; set; }
public Category Category { get; set; }
public Place Place { get; set; }
}
// POST: /EventManager/Edit/386
[HttpPost]
public ActionResult Edit(int id,FormCollection collection)
{
var theEvent = storeDB.Events.Find(id);
if (TryUpdateModel(theEvent))
{
storeDB.SaveChanges();
return RedirectToAction(\"Index\");
}
else
{
ViewBag.Categories = storeDB.Categories.OrderBy(g => g.Name).ToList();
ViewBag.Places = storeDB.Places.OrderBy(a => a.Name).ToList();
return View(theEvent);
}
}
public class EventCalendarEntities : DbContext
{
public DbSet<Event> Events { get; set; }
public DbSet<Category> Categories { get; set; }
public DbSet<Place> Places { get; set; }
}
EventDate (Datatype = date)
StartTime (Datatype = time)
EndTime (Datatype = time)
EventDate (Datatype = DateTime) e.g. 4/8/2011 12:00:00 AM
StartTime (Datatype = Timespan/time not sure) e.g. 08:30:00
EndTime (Datatype = Timespan/time not sure) e.g. 09:00:00
Line 75: if (TryUpdateModel(theEvent))
Line 76: {
Line 77: storeDB.SaveChanges();
Line 78: return RedirectToAction(\"Index\");
Line 79: }
解决方法
您可以使用以下代码从ѭ6中提取所有信息（您需要在
using
System.Data.Entity.Validation
System.Diagnostics
catch (DbEntityValidationException dbEx)
{
foreach (var validationErrors in dbEx.EntityValidationErrors)
{
foreach (var validationError in validationErrors.ValidationErrors)
{
Trace.TraceInformation(\"Property: {0} Error: {1}\",validationError.PropertyName,validationError.ErrorMessage);
}
}
}
catch {...}((System.Data.Entity.Validation.DbEntityValidationException)ex).EntityValidationErrors
((System.Data.Entity.Validation.DbEntityValidationException)$exception).EntityValidationErrors
catch (DbEntityValidationException dbEx)
{
foreach (var validationErrors in dbEx.EntityValidationErrors)
{
foreach (var validationError in validationErrors.ValidationErrors)
{
Trace.TraceInformation(
\"Class: {0},Property: {1},Error: {2}\",validationErrors.Entry.Entity.GetType().FullName,validationError.ErrorMessage);
}
}
}
public partial class MyDatabaseEntities : DbContext
{
public override int SaveChanges()
{
try
{
return base.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
foreach (var validationErrors in dbEx.EntityValidationErrors)
{
foreach (var validationError in validationErrors.ValidationErrors)
{
Trace.TraceInformation(\"Class: {0},validationError.ErrorMessage);
}
}
throw; // You can also choose to handle the exception here...
}
}
}
DbEntityValidationException
DbUpdateException
datetime2
SaveChanges
public class AppDbContext : DbContext
{
public override int SaveChanges()
{
try
{
return base.SaveChanges();
}
catch (DbEntityValidationException dbEntityValidationException)
{
throw ExceptionHelper.CreateFromEntityValidation(dbEntityValidationException);
}
catch (DbUpdateException dbUpdateException)
{
throw ExceptionHelper.CreateFromDbUpdateException(dbUpdateException);
}
}
public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken)
{
try
{
return await base.SaveChangesAsync(cancellationToken);
}
catch (DbEntityValidationException dbEntityValidationException)
{
throw ExceptionHelper.CreateFromEntityValidation(dbEntityValidationException);
}
catch (DbUpdateException dbUpdateException)
{
throw ExceptionHelper.CreateFromDbUpdateException(dbUpdateException);
}
}
public class ExceptionHelper
{
public static Exception CreateFromEntityValidation(DbEntityValidationException ex)
{
return new Exception(GetDbEntityValidationMessage(ex),ex);
}
public static string GetDbEntityValidationMessage(DbEntityValidationException ex)
{
// Retrieve the error messages as a list of strings.
var errorMessages = ex.EntityValidationErrors
.SelectMany(x => x.ValidationErrors)
.Select(x => x.ErrorMessage);
// Join the list to a single string.
var fullErrorMessage = string.Join(\"; \",errorMessages);
// Combine the original exception message with the new one.
var exceptionMessage = string.Concat(ex.Message,\" The validation errors are: \",fullErrorMessage);
return exceptionMessage;
}
public static IEnumerable<Exception> GetInners(Exception ex)
{
for (Exception e = ex; e != null; e = e.InnerException)
yield return e;
}
public static Exception CreateFromDbUpdateException(DbUpdateException dbUpdateException)
{
var inner = GetInners(dbUpdateException).Last();
string message = \"\";
int i = 1;
foreach (var entry in dbUpdateException.Entries)
{
var entry1 = entry;
var obj = entry1.CurrentValues.ToObject();
var type = obj.GetType();
var propertyNames = entry1.CurrentValues.PropertyNames.Where(x => inner.Message.Contains(x)).ToList();
// check MS SQL datetime2 error
if (inner.Message.Contains(\"datetime2\"))
{
var propertyNames2 = from x in type.GetProperties()
where x.PropertyType == typeof(DateTime) ||
x.PropertyType == typeof(DateTime?)
select x.Name;
propertyNames.AddRange(propertyNames2);
}
message += \"Entry \" + i++ + \" \" + type.Name + \": \" + string.Join(\"; \",propertyNames.Select(x =>
string.Format(\"\'{0}\' = \'{1}\'\",x,entry1.CurrentValues[x])));
}
return new Exception(message,dbUpdateException);
}
}
try
{
if (TryUpdateModel(theEvent))
{
storeDB.SaveChanges();
return RedirectToAction(\"Index\");
}
}
catch (System.Data.Entity.Validation.DbEntityValidationException dbEx)
{
Exception raise = dbEx;
foreach (var validationErrors in dbEx.EntityValidationErrors)
{
foreach (var validationError in validationErrors.ValidationErrors)
{
string message = string.Format(\"{0}:{1}\",validationErrors.Entry.Entity.ToString(),validationError.ErrorMessage);
// raise a new exception nesting
// the current instance as InnerException
raise = new InvalidOperationException(message,raise);
}
}
throw raise;
}
DropCreateDatabaseIfModelChanges
SaveChanges()
DbContext
public override int SaveChanges()
{
try
{
return base.SaveChanges();
}
catch (DbEntityValidationException ex)
{
string errorMessages = string.Join(\"; \",ex.EntityValidationErrors.SelectMany(x => x.ValidationErrors).Select(x => x.ErrorMessage));
throw new DbEntityValidationException(errorMessages);
}
}
SaveChanges()
// Get the key field name & value.
// This assumes your DbContext object is \"_context\",and that it is a single part key.
var e = ((IObjectContextAdapter)_context).ObjectContext.ObjectStateManager.GetObjectStateEntry(validationErrors.Entry.Entity);
string key = e.EntityKey.EntityKeyValues[0].Key;
string val = e.EntityKey.EntityKeyValues[0].Value;
var validationErrors = model.GetValidationErrors();
var h = validationErrors.SelectMany(x => x.ValidationErrors
.Select(f => \"Entity: \"
+(x.Entry.Entity)
+ \" : \" + f.PropertyName
+ \"->\" + f.ErrorMessage));
Try
Return MyBase.SaveChanges()
Catch dbEx As Validation.DbEntityValidationException
For Each [error] In From validationErrors In dbEx.EntityValidationErrors
From validationError In validationErrors.ValidationErrors
Select New With { .PropertyName = validationError.PropertyName,.ErrorMessage = validationError.ErrorMessage,.ClassFullName = validationErrors.Entry.Entity
.GetType().FullName}
Diagnostics.Trace.TraceInformation(\"Class: {0},[error].ClassFullName,[error].PropertyName,[error].ErrorMessage)
Next
Throw
End Try
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