find out the exact entity causing an exception in entity framework

Question

The entity framework gives me generic messages in the exception without telling me the exact entity and the attribute which caused the error. How do I get more information about

Answer 1

Here's the code I have in my solution:

try
{
    _context.SaveChanges();
}
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 inserting the current one as the InnerException
            raise = new InvalidOperationException(message , raise);
        }
    }
    throw raise;
}

You can use it as a basis to add into your solution ... it builds a nested set of exceptions with all the details from Entity Framework.

Answer 2

You need to write tests for repositories and in the base class for your tests:

try
{
    DbContext.SaveChanges();
}
catch (DbEntityValidationException e)
{
    e.EntityValidationErrors.SelectMany(error => error.ValidationErrors).ToList().ForEach(
    item => Console.WriteLine("{0} - {1}", item.PropertyName, item.ErrorMessage));
    throw;
}