Linq to Entities count不返回結果

我有以下linq查詢生成錯誤的sql（ProductId = PictureId）。我們轉而使用Devart Entity Developer來自動生成我們的POCO類，並彈出此問題。映射對我來說看起來是正確的，並且此查詢以前返回了正確的結果。映射看起來是否錯誤，或者查詢本身是不正確的？Linq to Entities count不返回結果

使用Entity Framework 5.0。

查詢：

var totalResults = _productRepository.Table.Where(a => a.Pictures.Any()).Count();

SQL：

SELECT 
[GroupBy1].[A1] AS [C1] 
FROM (SELECT 
    COUNT(1) AS [A1] 
    FROM [dbo].[Product] AS [Extent1] 
    WHERE EXISTS (SELECT 
     1 AS [C1] 
     FROM [dbo].[ProductPicture] AS [Extent2] 
     WHERE [Extent1].[ProductId] = [Extent2].[PictureId] // this should be ProductId = ProductId 
    ) 
) AS [GroupBy1]

流利映射：

 modelBuilder.Entity<Picture>() 
      .HasMany(p => p.Products) 
       .WithMany(c => c.Pictures) 
      .Map(manyToMany => manyToMany 
       .ToTable("ProductPicture", "dbo") 
       .MapLeftKey("ProductId") 
       .MapRightKey("PictureId"));

圖：

enter image description here