优化Linq to SQL查询,按多个字段分组

我的LINQ查询包含以下Group By语句:

Group p By Key = New With { _
.Latitude = p.Address.GeoLocations.FirstOrDefault(Function(g) New String() {"ADDRESS", "POINT"}.Contains(g.Granularity)).Latitude, _
.Longitude = p.Address.GeoLocations.FirstOrDefault(Function(g) New String() {"ADDRESS", "POINT"}.Contains(g.Granularity)).Longitude}

查询有效,但下面是上面的子句生成的SQL

SELECT [t6].[Latitude]
            FROM (
                SELECT TOP (1) [t5].[Latitude]
                FROM [dbo].[GeoLocations] AS [t5]
                WHERE ([t5].[Granularity] IN (@p0, @p1)) AND ([t5].[AddressId] = [t2].[Addr_AddressId])
                ) AS [t6]
            ) AS [value], (
            SELECT [t8].[Longitude]
            FROM (
                SELECT TOP (1) [t7].[Longitude]
                FROM [dbo].[GeoLocations] AS [t7]
                WHERE ([t7].[Granularity] IN (@p2, @p3)) AND ([t7].[AddressId] = [t2].[Addr_AddressId])
                ) AS [t8]
            ) AS [value2]

我不是SQL专家,但在我看来,这是一个相当次优的翻译。这应该是从第一条记录中选择纬度和经度的一个查询。也许SQL Server优化器会处理这个问题。但是有没有一种方法可以推动Linq生成一个更精简的SQL语句?

我也试过以下的……

Group p By Key = p.Address.GeoLocations.Where(Function(g) New String() {"ADDRESS", "POINT"}.Contains(g.Granularity)). _
Select(Function(g) New With {.Latitude = g.Latitude, .Longitude = g.Longitude}).FirstOrDefault

但这产生了一个错误:“按表达式分组只能包含服务器可比较的非常量标量。”