使用LINQ将int列连接到字符串列

Question

尝试了很多搜索中的各种组合，但似乎仍无法正常工作。我有以下查询：

var r = from a in ctx.DGApprovedLinks
         join h in ctx.DGHosts on a.HostID equals h.ID
         join c in ctx.DGConfigs on SqlFunctions.StringConvert((double)a.ResponseCode) equals c.SubType
         where c.Type == "HTTP Status"
         select new
         {
             a.ID,
             a.HostID,
             h.URL,
             a.SourceURL,
             a.TargetURL,
             c.Value,
             a.ExtFlag
         };

但未能返回任何结果。我在SQL事件探查器中得到以下内容：

SELECT 
1 AS [C1], 
[Extent1].[ID] AS [ID], 
[Extent1].[HostID] AS [HostID], 
[Extent2].[URL] AS [URL], 
[Extent1].[SourceURL] AS [SourceURL], 
[Extent1].[TargetURL] AS [TargetURL], 
[Extent3].[Value] AS [Value], 
[Extent1].[ExtFlag] AS [ExtFlag]
FROM   [dbo].[DGApprovedLink] AS [Extent1]
INNER JOIN [dbo].[DGHost] AS [Extent2] ON [Extent1].[HostID] = [Extent2].[ID]
INNER JOIN [dbo].[DGConfig] AS [Extent3] ON ((STR( CAST( [Extent1].[ResponseCode] AS float))) = [Extent3].[SubType]) OR ((STR( CAST( [Extent1].[ResponseCode] AS float)) IS NULL) AND ([Extent3].[SubType] IS NULL))
WHERE N'HTTP Status' = [Extent3].[Type]

非常感谢任何帮助。