使用列表中的 AddRange 会导致多个数据库行程

这是我继承的代码，而不是我的设计。

正在进行一个大查询以返回对象列表。然后，查询结果用于创建自定义对象列表。有大量的循环，并且存在以获得不同的值，例如县、州等。为了优化代码，我尝试从查询结果中选择不同的值，并使用 AddRange 将它们添加到新集合中。但是，这会导致对每个值调用 SQL。

初始查询

        using (var db = new StorageEntities())
        {
            db.Configuration.AutoDetectChangesEnabled = false;
            List<CompanyTitleFeeSchedule> list = db.CompanyTitleFeeScheduleCompanies
                .Include(x => x.Company)
                .Include(x => x.CompanyTitleFeeSchedule)
                .Include(x => x.CompanyTitleFeeSchedule.CompanyTitleFeeScheduleAreas)
                .Include(x => x.CompanyTitleFeeSchedule.CompanyTitleFeeScheduleCompanies)
                .Include(x => x.CompanyTitleFeeSchedule.CompanyTitleFeeScheduleAreas.Select(t => t.County))
                .Include(x => x.CompanyTitleFeeSchedule.CompanyTitleFeeScheduleAreas.Select(t => t.County.State))
                .Where(x => x.CompanyID == id || x.Company.ParentCompanyID == id)
                .Select(x => x.CompanyTitleFeeSchedule).Distinct().ToList();
            return list.Select(item => new VM.CompanyTitleFeeScheduleViewModel(item)).ToList();
        }

**在构造函数VM.CompanyTitleFeeScheduleViewModel中，它具有CountyViewModel列表，我正在尝试从查询结果中填充不同的县。这会导致调用每个不同县的数据库。即使我需要的值已经在查询结果中。既然列表已经枚举，为什么实体需要返回到数据库？**

           //Get a list of distinct counties and add them to the collection
            Counties.AddRange((from c in data.CompanyTitleFeeScheduleAreas
                group c by c.CountyID
                into cty
                select cty.First())
                .Select(cty => new CountyViewModel
                {
                    CountyID = cty.CountyID,
                    Name = cty.County.Name,
                    StateID = cty.County.StateID
                }));

...
.Select(x => x.CompanyTitleFeeSchedule)
.Include(x => x.CompanyTitleFeeScheduleAreas) // added this.
...