如何将 SQL Inner Join、Group By 转换为 Linq？

Question

这里我有 SQL 查询，现在我正在尝试将其转换为 linq，但不知道如何去做，并且卡在从 ChapterQuestion 表中获取 ChapterId。

任何有关翻译的帮助都将不胜感激。
谢谢

下面是我的sql查询

SELECT  CQ.ChapterId,CQS.SetNumber,count(distinct CQ.ChapterQuestionId) as questioncount FROM 
[dbo].[ChapterQuestion] AS CQ 
JOIN [dbo].[ChapterQuestionSet] AS CQS ON CQ.ChapterQuestionSetId = CQS.ChapterQuestionSetId
WHERE CQ.ChapterId = 1 group by CQS.SetNumber,CQ.ChapterId

下面是我的linq

 var list = (from CQS in uow.Repository<ChapterQuestionSet>().GetAll().ToList()
                    join CQ in uow.Repository<ChapterQuestion>().FindBy(x => x.ChapterId == chapterId).ToList()
                    on CQS.ChapterQuestionSetId equals CQ.ChapterQuestionSetId
                    group CQ by CQS into G1
                   
                    select new ChapterQuestionSetVM
                    {
                        ChapterQuestionSetId = G1.Key.ChapterQuestionSetId,
                        Count = G1.Count(t => t.ChapterQuestionSetId != null),
                        QuestionSetNo = $"Question set {G1.Key.SetNumber}",
                       ChapterId = // how do i get chapterid from ChapterQuestion
                    }).ToList();

Answer 1

这是更正的查询。我希望Repository.GetAll() 返回IQueryable？ 此查询仅适用于 EF Core 5.x

var query = 
    from CQS in uow.Repository<ChapterQuestionSet>().GetAll()
    join CQ in uow.Repository<ChapterQuestion>().GetAll() on CQS.ChapterQuestionSetId equals CQ.ChapterQuestionSetId
    where CQ.ChapterId == 1
    group CQ by new { CQS.SetNumber, CQ.ChapterId } into G1
    select new ChapterQuestionSetVM
    {
        ChapterId = G1.Key.ChapterId
        QuestionSetNo = $"Question set {G1.Key.SetNumber}",
        Count = G1.Select(t => t.ChapterQuestionSetId).Distinct().Count(),
    };
 
 var list = query.ToList();