EntityFramework错误处理

public void Insert(PageHost entity){try{db.pagehost.Add(entity);db.SaveChanges();}catch (DbEntityValidationException ep){CatchException(ep);}catch (Exception ep){throw ep;}}private void CatchException(DbEntityValidationException ep){StringBuilder sb = new StringBuilder();foreach (DbEntityValidationResult item in ep.EntityValidationErrors){foreach (string pp in item.Entry.OriginalValues.PropertyNames){sb.AppendLine(item.Entry.Member(pp).CurrentValue.ToString());}foreach (DbValidationError i in item.ValidationErrors){throw new Exception(string.Format("{0}\t{1}\t{2}", i.PropertyName, i.ErrorMessage, sb.ToString()));}}}