How to handle System.Data.Entity.Validation.DbEntityValidationException? [duplicate]

Answer 1

You can override the SaveChanges, to handle this exception and provide better exception details.

You can create a class "next" to your context class... the full code for that class is as follow:

using System.Data.Entity;
using System.Data.Entity.Validation;
using System.Linq;

namespace MyNamespace
    {
        public partial class MyContext : DbContext
        {
            // Override base SaveChanges to expand out validation errors so client gets an actually helpful message
            public override int SaveChanges()
            {
                try
                {
                    return base.SaveChanges();
                }
                catch (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);

                    // Throw a new DbEntityValidationException with the improved exception message.
                    throw new DbEntityValidationException(exceptionMessage, ex.EntityValidationErrors);
                }
            }
        }
    }

Check this for more information: http://devillers.nl/blog/improving-dbentityvalidationexception/