Entity Framework 查询：包含在何处

Question

我想获取所有图层组并包括（预先加载）具有特定 url 的图层。

这是我的表格：

 - LayerGroup (id, List<Layer>layers and more...) 
 - Layer(id, url, List<Attribute>attributes and more...) 
 - Attribute (id and more...)

这就是我到目前为止所得到的。

var groups = _context.LayerGroups
                    .Where(group => group.IsActive)
                    .Where(g => g.Layers.All(l => l.IsActive == true))
                    .Where(g => g.Layers.All(l => l.Url == "example1"))
                    .Include(g => g.Layers)                     
                    .ThenInclude(layer => layer.Attributes)
                    .Include(group => group.Layers).ThenInclude(layer => layer.SearchEngines)
                    .ToList();

但它似乎只有在所有图层都处于活动状态并且具有 url 示例 1 时才会获得组。我想获得正确 Url 的图层，即使这些组具有其他 url:s.

的图层

Answer 1

According to this 您无法过滤 Include 和 ThenInclude 集合，但您可以使用基于 Include 的条件过滤父集合。如果需要，您可以按如下方式编写查询：

var groups = _context.LayerGroups.Where(group => group.IsActive)
                    .Include(g => g.Layers)
                        .ThenInclude(layer => layer.Attributes)
                    .Include(group => group.Layers)
                        .ThenInclude(layer => layer.SearchEngines)
                    .Where(g => g.Layers.Any(l => l.IsActive == true && l => l.Url == "example1"))
                    .ToList();

Entity Framework 查询：包含在何处

Entity Framework Query : Include with where

linq

entity-framework

include

eager-loading