Comment écrire cette requête SQL moyenne dans LINQ

Question

Voici le SQL que je voudrais courir:

DECLARE @StartDt DATETIME, @EndDt DATETIME 
SET @StartDt='2009-01-01' 
SET @EndDt='2010-06-01' 

SELECT 
AVG(DATEDIFF(day, CreatedDt, CompletedDt)) 
AVG(DATEDIFF(day, CreatedDt, ComplianceDt)) 
FROM MyTable 
WHERE RequestDt BETWEEN @StartDt AND @EndDt 

Cela peut être exprimé en Linq (C#) et ont tout terme sur la base de données?

Answer 1

DateTime startDt = new DateTime(2009, 1, 1); 
DateTime endDt = new DateTme(2010, 6, 1); 

var query = dc.MyTables 
    .Where(x => startDt <= x.RequestDate && x.RequestDt <= endDt) 
    .GroupBy(x => 1) //unsure about this group by 
    .Select(g => new 
    { 
    FirstAvg = g.Average(x => 
     SqlMethods.DateDiffDay(x.CreatedDt, x.CompletedDt)), 
    SecondAvg = g.Average(x => 
     SqlMethods.DateDiffDay(x.CreatedDt, x.ComplianceDt)) 
    }); 

var row = query.Single();