无法在 Grouping 上翻译 LINQ 表达式

Question

我有 LINQ 表达式来获取前 15 个最常用的答案

这是表达式

 var latestAnswers = await _dbContext.TextAnswers.Include(x => x.CompanySurvey).ThenInclude(x => x.Survey)
        .Where(x => x.CompanySurvey.Survey.FiscalYear == 2022)
        .GroupBy(x => x.Answer)
        .OrderByDescending(g => g.Count())
        .Take(15)
        .ToListAsync();

但我得到了这个错误

LINQ 表达式 'DbSet() .Include(x => x.CompanySurvey) .ThenInclude(x => x.Survey) .Where(x => x.CompanySurvey.Survey.FiscalYear == (int?)2022 ) .GroupBy(x => x.Answer) .OrderByDescending(g => g .AsQueryable() .Count()) .Take(__p_0)' 无法翻译。以可翻译的形式重写查询，或通过插入对“AsEnumerable”、“AsAsyncEnumerable”、“ToList”或“ToListAsync”的调用显式切换到客户端评估。请参阅https://go.microsoft.com/fwlink/?linkid=2101038 了解更多信息。

我不明白为什么不能翻译。

我该如何解决这个问题？

Answer 1

EF Core 6 必须支持此类查询，但看起来完整的实现支持已移至 EF Core 7

对话后看起来不需要从数据库中获取分组记录，而只是分组键和计数

var latestAnswers = await _dbContext.TextAnswers
    .Where(x => x.CompanySurvey.Survey.FiscalYear == 2022)
    .GroupBy(x => x.Answer)
    .Select(g => new { Answer = g.Key, Count = g.Count() })
    .OrderByDescending(x => x.Count)
    .Take(15)
    .ToListAsync();

Answer 2

我这样重写我的代码

 var latestAnswersQuery = await _dbContext.TextAnswers
        .Include(x => x.CompanySurvey).ThenInclude(x => x.Survey)
        .Where(x => x.CompanySurvey.Survey.FiscalYear == 2022)
        .ToListAsync();

    var latestAnswers = latestAnswersQuery.GroupBy(x => x.Answer).OrderByDescending(g => g.Count()).Take(15);
    return latestAnswers;

现在一切都很好