GROUP BY和LINQ

Question

HAVING我想這個代碼轉換爲LINQ：

select t1.title, COUNT(*)as num 
from t1 INNER join t2 on t2.gId = t1.Id 
group by t1.title, t1.cId 
having t1.cId = 2 

我想這下面的代碼：

from p in db.t1s join r in db.t2s on p.Id equals r.gId 
where p.cId == 2 
group p by p.title into g 
select new{ name = from o in g select o.title, num = g.Count()} 

但是，這並不正確返回計數。

請指導我怎樣才能解決這個問題

感謝

Answer 1

無採樣數據它很難得到它的權利，但嘗試這個片段

from p in db.t1s 
join r in db.t2s on p.Id equals r.gId 
where p.cId == 2 
group p by new {p.title, p.cId} into grouped 
select new{ name = grouped.Key.title, num = grouped.Count()} 

此外，請注意，這個SQL語句：

select t1.title, COUNT(*)as num 
from t1 INNER join t2 on t2.gId = t1.Id 
group by t1.title, t1.cId 
having t1.cId = 2 

由於COUNT（*）將始終返回1。原因是你有過濾t1.cId = 2和t1.cId分組作爲第二個參數。