小编the*_*son的帖子

我在使用EF Codefirst正确保存多对多关系时遇到问题.我已正确建模我的类并使用Fluent-API正确建模连接表.我认为这个问题与使用断开连接的DTO有关.当我将更改保存到父实体(公寓)时,父实体(例如Title和UserId)上的scalular属性保存正确,但对子实体(设施)的更改不会保存到多对多表.

这是有助于澄清事物的代码流:

public ICommandResult Execute(CreateOrUpdateCondoCommand command)
    {
        ICollection<Amenity> amenities = new List<Amenity>();

        foreach (var item in command.Amenities)
        {
            Amenity amenity = new Amenity { AmenityId = item.AmenityId };
            amenities.Add(amenity);
        }

        var condo = new Condo
        {
            [...other properties]
            Title = command.Title,               
            Amenities = amenities             
        };                  

        if (condo.CondoId == 0)
        {
            condoRepository.Add(condo);
        }
        else
        {
            condoRepository.Update(condo);
        }

        unitOfWork.Commit();

        return new CommandResult(true);
    }

    /// <summary>
    /// Updates the entity.
    /// </summary>
    /// <param name="entity">The entity</param>
    public virtual void Update(T entity)
    { …