Question

此代码在升级到核心2.2之前运行良好我不明白参数名称：键是什么。我还采用了通过SQL事件探查器生成的代码，并直接在sql management studio中运行，并且代码执行时没有任何错误

此错误是在await _context.SaveChangesAsync();

上生成的

Aslo注意，当我再次将应用程序降级为.net core 2.1时，它可以正常工作

产生的异常是

  An exception occurred in the database while saving changes for context type 'RtasWebApp.Data.ApplicationDbContext'.
Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: key
   at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
   at System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue& value)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.FindIdentityMap(IKey key)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.GetDependents(InternalEntityEntry principalEntry, IForeignKey foreignKey)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.NavigationFixer.KeyPropertyChanged(InternalEntityEntry entry, IProperty property, IReadOnlyList`1 containingPrincipalKeys, IReadOnlyList`1 containingForeignKeys, Object oldValue, Object newValue)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryNotifier.KeyPropertyChanged(InternalEntityEntry entry, IProperty property, IReadOnlyList`1 keys, IReadOnlyList`1 foreignKeys, Object oldValue, Object newValue)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectKeyChange(InternalEntityEntry entry, IProperty property)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.PropertyChanged(InternalEntityEntry entry, IPropertyBase propertyBase, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryNotifier.PropertyChanged(InternalEntityEntry entry, IPropertyBase property, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetProperty(IPropertyBase propertyBase, Object value, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetCurrentValue(IPropertyBase propertyBase, Object value)
   at Microsoft.EntityFrameworkCore.Update.ColumnModification.set_Value(Object value)
   at Microsoft.EntityFrameworkCore.Update.ModificationCommand.PropagateResults(ValueBuffer valueBuffer)
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeResultSetWithPropagationAsync(Int32 commandIndex, RelationalDataReader reader, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeAsync(RelationalDataReader reader, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeAsync(RelationalDataReader reader, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(DbContext _, ValueTuple`2 parameters, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IReadOnlyList`1 entriesToSave, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: key
   at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
   at System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue& value)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.FindIdentityMap(IKey key)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.GetDependents(InternalEntityEntry principalEntry, IForeignKey foreignKey)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.NavigationFixer.KeyPropertyChanged(InternalEntityEntry entry, IProperty property, IReadOnlyList`1 containingPrincipalKeys, IReadOnlyList`1 containingForeignKeys, Object oldValue, Object newValue)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryNotifier.KeyPropertyChanged(InternalEntityEntry entry, IProperty property, IReadOnlyList`1 keys, IReadOnlyList`1 foreignKeys, Object oldValue, Object newValue)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectKeyChange(InternalEntityEntry entry, IProperty property)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.PropertyChanged(InternalEntityEntry entry, IPropertyBase propertyBase, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryNotifier.PropertyChanged(InternalEntityEntry entry, IPropertyBase property, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetProperty(IPropertyBase propertyBase, Object value, Boolean setModified)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetCurrentValue(IPropertyBase propertyBase, Object value)
   at Microsoft.EntityFrameworkCore.Update.ColumnModification.set_Value(Object value)
   at Microsoft.EntityFrameworkCore.Update.ModificationCommand.PropagateResults(ValueBuffer valueBuffer)
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeResultSetWithPropagationAsync(Int32 commandIndex, RelationalDataReader reader, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeAsync(RelationalDataReader reader, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeAsync(RelationalDataReader reader, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(DbContext _, ValueTuple`2 parameters, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IReadOnlyList`1 entriesToSave, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)

任何想法都值得赞赏

Answer 1

我遇到了同样的问题，并在他们的GitHub上创建了这个问题：https://github.com/aspnet/EntityFrameworkCore/issues/14419

对我来说，问题是我在Startup.cs中使用services.AddDbContextPool<ApplicationDbContext>(options =>。使用连接池版本EF时似乎存在错误。尝试通过删除单词Pool（services.AddDbContext<ApplicationDbContext>(options =>）来恢复为普通版本的DbContext，看看问题是否消失

Answer 2

那是.net core 2.2.2中的错误（请参阅this）。就我而言，我安装了.net core 2.2.3，此问题已解决。您可以从here下载它。

Answer 3

我遇到了这个问题，试图同时更新许多记录并调用SaveChanges（）。当更新查询花费更多时间来更新记录时，可能会发生超时，这可能会发生。您可以更新CommandTimeout作为解决方案。在您的数据上下文类中，将此添加到构造函数中。

Database.SetCommandTimeout（10000）;

因此您的代码将如下所示。

public DataContext(DbContextOptions<DataContext> options, UserContext userContext)
{
    _userContext = userContext;
    _tenantDbInfo = tenantDbInfo;
    Database.SetCommandTimeout(10000);
}

升级到.net core 2.2后，通过EF插入失败并显示错误

3 个答案: