LINQ - 3子由與組選擇計數

Question

SQL：

SELECT i.name, l.city, COUNT(l.city) AS num 
FROM locality l 
JOIN event e ON e.ID_locality = l.ID 
JOIN program p ON p.ID_event = e.ID 
JOIN interpreter i ON i.ID = p.ID_interpreter 
WHERE i.name = 'XXXX' 
GROUP BY l.city 
HAVING COUNT(l.city) = (
SELECT MAX(num) 
FROM (SELECT COUNT(city) AS num 
FROM (SELECT l.city FROM locality l 
JOIN event e ON e.ID_locality = l.ID 
JOIN program p ON p.ID_event = e.id 
JOIN interpreter i ON i.ID = p.ID_interpreter 
WHERE i.name = 'XXXX' 
GROUP BY l.city) tmp) tmp2) 

LINQ：

var q4 = from l in db.locality 
     join e in db.event on l.ID equals e.ID_locality 
     join p in db.program on e.ID equals p.ID_event 
     join i in db.interpreter on p.ID_interpreter equals i.ID 
     where i.name == "XXXX" 
     group l by l.city into grp 

你好，我 RLY有嚴重的問題，這種選擇在LINQ。我在SQL中編寫了這個選擇，但我真的不知道如何通過計數來使用多個子選擇...我想選擇解釋器「XXXX」最經常演示的城市以及解釋器在那裏演示的次數。我也檢查了enter link description here，但當我嘗試使用它時，它並沒有幫助我。如果有人能幫助我，我會很開心。 爲了更好的方向：

Answer 1

我不確定，但我希望你能這樣做。

var query = (from l in db.locality 
      join e in db.event on l.ID equals e.ID_locality 
      join p in db.program on e.ID equals p.ID_event 
      join i in db.interpreter on i.ID equals p.ID_interpreter 
      group l by new { i.name, l.city } into g 
      where i.name == "XXXX" && 
      g.Count(x => x.city) == (from l in db.locality 
              join e in db.event on l.ID equals e.ID_locality 
              join p in db.program on e.ID equals p.ID_event 
              join i in db.interpreter on i.ID equals p.ID_interpreter 
              where i.name == "XXXX"     
              group l by l.city into g 
              select new 
              { 
               cityCount = g.Count(x => x.city) 
              }).Max() 

      select new 
      { 
       g.key.name, 
       g.key.city, 
       maxNum = g.count(x => x.city) 
      }).ToList();