entity-framework - 有条件的急切加载？

Question

我想有条件地加载一个实体和它的 child (我只想在 child.IsActive == true 时急切加载 child )。我如何执行以下操作？

var parent = 
    from p in db.tblParents.Include("tblChildren") <-- where tblChildren.IsActive == true
    where p.PrimaryKey == 1
    select p;

注意:我不想返回匿名类型。

谢谢。

Answer 1

这样做的一种方法是:

var parent = from p in db.tblParents where p.PrimaryKey == 1
             select new {
                 Parent = p,
                 Children = p.tblChildren.Where(c => c.IsActive == true)
             }.ToList();

但是，您可能不喜欢返回匿名类型的想法，那么我建议这样编码:

var parent = (from p in db.tblParents where p.PrimaryKey == 1).Single();
var childrens = ctx.Contacts.Where(c => c.ParentID == 1 && c.IsActive == true);
foreach (var child in childrens) {
   parent.tblChildren.Add(child);
}