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mlightsout's avatar
mlightsout
Copper Contributor
Jul 25, 2023

PropertyNames migration error from .NET Framework to .NET 6

Does anyone know how to fix this code to get it to work for .NET 6?  I have researched the MS website documentation and I'm still unsure how to proceed.  In the code below, the error occurs on the PropertyNames word.  I've left out some code for brevity but I hope there is enough code posted to help you understand what I'm trying to accomplish.

var modifiedEntities = ChangeTracker.Entries().Where(p => p.State == EntityState.Modified).ToList();

foreach (var change in modifiedEntities)
{
     var entityName = change.Entity.GetType().BaseType.Name;
     var primaryKey = GetPrimaryKeyValue(change);

     foreach (var prop in change.OriginalValues.PropertyNames)  //ERROR occurs on PropertyNames on this line.
     {
          //code that writes the OldValue and NewValue to ChangeLog database table is here
     }
}

 

ASP.NET (Classic)
ASP.NET Core
mvc

5 Replies

  • shazmaafzal's avatar
    shazmaafzal
    Copper Contributor
    Aug 13, 2023

    Hi mlightsout,

    In .NET 6, the Entity Framework has undergone significant changes, and the syntax you are using for accessing property names has also changed. In previous versions of Entity Framework, you could use OriginalValues.PropertyNames to get the property names of the original values of an entity during change tracking. However, this approach is no longer available in Entity Framework Core (which is used in .NET 6 and later versions).

    To achieve the same functionality in Entity Framework Core 6, you need to use the OriginalValues.Properties property and iterate over the properties to get their names. Here's how you can modify your code to work with .NET 6:

    var modifiedEntities = ChangeTracker.Entries().Where(p => p.State == EntityState.Modified).ToList();

foreach (var change in modifiedEntities)
{
     var entityName = change.Entity.GetType().BaseType.Name;
     var primaryKey = GetPrimaryKeyValue(change);

     var originalValues = change.OriginalValues;

     foreach (var prop in originalValues.Properties)
     {
          var propertyName = prop.Name;
          var originalValue = originalValues[prop];

          //code that writes the OldValue and NewValue to ChangeLog database table is here
     }
}

    In the modified code, originalValues.Properties returns a collection of IProperty objects representing the properties of the entity, and you can access the property name using the Name property of each IProperty object.

    Make sure to adjust the rest of your code to use the originalValue obtained from originalValues[prop] to access the old value of the property, and proceed with writing to the ChangeLog database table.

    • mlightsout's avatar
      mlightsout
      Copper Contributor
      Aug 14, 2023

      shazmaafzal thank you for the help.  I was stumped and the documentation was confusing to me.  This gets me going in the right direction.  Much appreciated!

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