轉換此連接的SQL查詢LINQ

Question

我如何轉換這個SQL查詢來LINQ

select sum(a.Count),b.PeriodDesc from dbo.tbl_Sample a,dbo.tbl_Period b 
where a.PeriodID=b.PeriodID group by PeriodDesc 

tbl_Period -PeriodID，PeriodDesc
tbl_Sample - ID，計數，PeriodID

Answer 1

讓我們假設YourContext產生上下文和導航屬性之間的tbl_Period和tbl_Sample，比查詢看起來像：

using(var db = new YourContext()) 
    { 
      var result = db.tbl_Sample.GroupBy(p=>p.tbl_Period.PeriodDesc) 
      .Select(p => new {p.Key, p.Count()}) 
      //whateve you want to do ... 
    } 

Answer 2

請檢查

var result = (from a in tbl_Sample 
group a by a.PeriodDesc into abc       
join b in tbl_Period on abc.FirstOrDefault().PeriodID equals b.PeriodID  
select new ModelName { 
    SumofCount = abc.sum(m => m.Count), 

    PeriodDesc = b.PeriodDesc 
}).tolist(); 

Answer 3

嘗試用這種

var joinedTables = from p in listPeriod 
join s in listSample on p.PeriodID equals s.PeriodID 
select new { p.PeriodDesc, s.Count }; 

var result = from p in joinedTables 
group p by p.PeriodDesc into g 
select new { PeriodDesc = g.Key, Sum = g.Sum(p=>p.Count)}; 

OFC你必須改變listPeriod和listSample用正確的集合（或表實體）