c# - Entity Framework .include 性能问题

Question

我有以下非常慢的查询。我是 Entity Framework 的新手，我相信它必须与 Eager Loading、Lazy Loading 或 Explicit Loading 相关。需要帮助优化以下 C# 语句。

var queryResult = CurrentSession.Set<SomeType_T>().Include(a => a.SomeType1_T)
                                .Include(a => a.SomeType1_T.Catalog_Type_T)
                                .Include(a => a.SomeType1_T.SomeType4_T)
                                .Include(a => a.SomeType1_T.SomeType2_T)
                                .Include("SomeType1_T.SomeType2_T.SomeType3_T")
                                .Include(a => a.SomeType1_T.SomeType4_T.SomeType5_T)
                                .Include(a => a.SomeType1_T.SomeType5_T)
                                .Include(a => a.SomeType1_T.Questions_T)
                                .Include(a => a.SomeType1_T.Questions_T.Question_Type_T)
                                .Include(a => a.SomeType1_T.Members_T)
                                .Include(b => b.SomeMasterType_T)
                                .Include(b => b.SomeMasterType_T.SomeMasterType1_T)
                                .Include(c => c.SomeType6_T)
                                .Include(d => d.SomeType7_T)
                                .Include(d => d.SomeType8_T)
                                .Include(d => d.SomeType8_T1)
                                .Where(t => t.SomeType9_T == _MatchThisKey);

Answer 1

您可以通过从数据库创建 2 个或更多小数据请求来提高许多包含的性能，如下所示。根据我的经验，您可以为每个查询提供最多 2 个包含。超过这个数量会带来非常糟糕的性能。是的，这是丑陋的。但它会带来非常好的性能提升。你也可以尝试感受一下:)

注意:这只是一个例子。

var userData = from u in db.Users
                        .Include(p=>p.UserSkills)
                        .Include(p=>p.UserIdeas)
                        .FirstOrDefault();

 userData = from u in db.Users
                    .Include(p=>p.UserFriends)
                    .Include(p=>p.UserFriends1)
                    .FirstOrDefault();

上面将使用多个遍历从数据库中获取小数据集。