Entity Framework dbSet.Include(x=>x.Offer.Images.Where(y=>y.IsDeleted == false))

Question

我应该如何将此查询转换为有效的 Entity Framework 查询？

dbSet.Include(x=>x.Offer.Images.Where(y=>y.IsDeleted == false))

Where 子句抛出异常：

The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference navigation properties and the Select operator for collection navigation properties.

我已经尝试过第三方库 IncludeFilter，它有效。但是它不允许我使用另一个包括：

dbSet.Include(x=>x.Offer.Images.Where(y=>y.IsDeleted == false)).Include(x=>x.Demand)

非常感谢:-)

Answer 1

Include 只是告诉 EF 预先加载相关实体的标记。它不支持预先加载选定的亲属子集，例如活动项目。

使用软删除模型时 (IsDeleted/IsActive) 将使用活动子项填充视图模型。为读取操作返回视图模型的好处是您可以避免潜在的延迟加载情况，而只需检索您需要使用的数据。对于编辑操作，我会预先加载相关数据，并且通常需要活动和非活动记录。

var viewModels = dbset.Select(x => new MyVM
{
  Objectid = x.ObjectId,
  // ...
  Offer = new OfferViewModel
  {
    OfferId = x.Offer.OfferId,
    // ...
    Images = x.Offer.Images
      .Where(i => !i.IsDeleted) // Load only active images
      .Select(i => new ImageViewModel 
      {
        ImageId = i.ImageId,
        //...
      }).ToList()
  }
}

请注意，这不需要显式 .Include() 语句，只需加载您需要的数据。

当我去保存对实体图的更改时，我会用 .Include(x => x.Order).Include(x => x.Order.Images) 加载根实体以确保我包含所有相关数据。 EF 应该在应用更新之前了解完整集合，以避免出现重复记录插入尝试等意外情况。

Answer 2

I already tried third party library IncludeFilter, which works. However it doesn't allow me to use another include:

开始使用IncludeFilter时，即使不过滤也需要一直使用下去。

dbSet.IncludeFilter(x=>x.Offer.Images.Where(y=>y.IsDeleted == false))
.IncludeFilter(x=>x.Demand)

Entity Framework dbSet.Include(x=>x.Offer.Images.Where(y=>y.IsDeleted == false))

Entity Framework dbSet.Include(x=>x.Offer.Images.Where(y=>y.IsDeleted == false))

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