entity-framework - 如何详细记录我的实体错误

Question

如果发生任何错误，我想将实体类的属性值存储为额外的值。执行此操作的最佳做​​法是什么？我认为，通过反射获取值并将它们写入数据库是一个很好的解决方案，但它又产生了另一个问题。我怎样才能达到所有值，包括集合的值，换句话说，子对象的值。我试图通过使用反射来达到目的，但我卡住了，失败了。如果我的解决方案是错误的，我愿意接受任何合适的解决方案和建议:)

例如:

public class Author : BaseEntity
{

    /// <summary>
    /// Gets or sets a value indicating the author's name
    /// </summary>
    public string Name { get; set; }

    /// <summary>
    /// Gets or sets a value indicating the author's surname
    /// </summary>
    public string Surname { get; set; }

    /// <summary>
    /// Gets or sets a value indicating the author's birthdate
    /// </summary>
    public DateTime BirthDate { get; set; }

    /// <summary>
    /// Gets or sets a value indicating the author's death of date
    /// </summary>
    public DateTime DeathDate { get; set; }

    /// <summary>
    /// Gets or sets a value indicating rating entity
    /// </summary>
    public virtual AuthorRating Rating { get; set; }

    /// <summary>
    /// Gets or sets a value indicating idenitifier of the author's nationality
    /// </summary>
    public int NationalityId { get; set; }

    /// <summary>
    /// Gets or sets a value indicating the author's nationality
    /// </summary>
    public virtual Nation Nationality { get; set; }

    /// <summary>
    /// Gets or sets the collection of votes
    /// </summary>
    public virtual ICollection<AuthorVote> HavingVotes { get; set; }

    /// <summary>
    /// Gets or sets the collection of quotes which he/she said
    /// </summary>
    public virtual ICollection<Quote> OwnQuotes { get; set; }

    /// <summary>
    /// Gets or sets the collection of favourited rows by user
    /// </summary>
    public virtual ICollection<UserFavouriteAuthor> Favouriteds { get; set; }

}

例如，如何使用反射递归地访问 Author.Qutes.QuoteVotes 类及其值及其子类？

Answer 1

要处理 DbEntityValidationException，请将与 DbContext 相关的代码放在 try catch block 中，并将其用于异常

public void AppendValidationErrors(Exception e)
{
    DbEntityValidationException ex = e is DbEntityValidationException ?
        e as DbEntityValidationException : null ;

    if (ex == null) { log.Info(e); return; }

    foreach (var eve in ex.EntityValidationErrors)
    {
        log.Info(string.Format("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
            eve.Entry.Entity.GetType().Name, eve.Entry.State));

        foreach (var ve in eve.ValidationErrors)
        {
            log.Info(string.Format("- Property: \"{0}\", Error: \"{1}\"",
                ve.PropertyName, ve.ErrorMessage));
        }
    }
}

要获取属性值，可以使用 EF 的 DbPropertyValues

    public static void PrintValues(DbPropertyValues values) 
    { 
        foreach (var propertyName in values.PropertyNames) 
        { 
            Console.WriteLine("Property {0} has value {1}", 
                              propertyName, values[propertyName]); 
        } 
    }

   PrintValues(context.Entry(User).GetDatabaseValues());