protected override System.Data.Entity.Validation.DbEntityValidationResult ValidateEntity(DbEntityEntry entityEntry, System.Collections.Generic.IDictionary<object, object> items)

{

    if (entityEntry.Entity is Student)

    {

        if (entityEntry.CurrentValues.GetValue<string>("StudentName") == "")

        {

            var list = new List<System.Data.Entity.Validation.DbValidationError>();

            list.Add(new System.Data.Entity.Validation.DbValidationError("StudentName", "StudentName is required"));

            return new System.Data.Entity.Validation.DbEntityValidationResult(entityEntry, list);

        }

    }

    return base.ValidateEntity(entityEntry, items);

}

try

{

    using (var ctx = new SchoolDBEntities())

    {

        ctx.Students.Add(new Student() { StudentName = "" });

        ctx.Standards.Add(new Standard() { StandardName = "" });

        ctx.SaveChanges();

    }

}

catch (DbEntityValidationException dbEx)

{

    foreach (DbEntityValidationResult entityErr in dbEx.EntityValidationErrors)

    {

        foreach (DbValidationError error in entityErr.ValidationErrors)

        {

            Console.WriteLine("Error Property Name {0} : Error Message: {1}",

                                error.PropertyName, error.ErrorMessage);

        }

    }

}