將SQL轉換爲LINQ：將結果選擇到模型

Question

我不熟悉LINQ，任何人都可以幫助我嗎？ 在此先感謝。

我的模型：

public class OrderOverViewModel 
{ 
    public int Quantity { get; set; } 
    public String ACCN { get; set; } 
    public DateTime OrderDate { get; set; } 
} 

這是SQL：

SELECT COUNT(*) AS HowMany, 
     DATEADD(dd, 0, DATEDIFF(dd, 0, RXS_OrderDate)) AS OrderDate, 
     RXS_ACCN AS ACCN 
FROM RXS_RxJobs 
WHERE DATEDIFF(WK, RXS_OrderDate, GETDATE()) = 1 
GROUP BY RXS_ACCN, DATEADD(dd, 0, DATEDIFF(dd, 0, RXS_OrderDate)) 

結果在SSMS：

我想選擇的結果填補了模型，如何實現這一目標？ 再次感謝。

Answer 1

使用SqlFunctions.DateDiff方法來獲取當前日期和訂單日期之間周。您也可以簡單地通過DateDateTime對象的屬性獲取日期的部分日期。查詢應該是這樣的：

from j in context.RXS_RxJobs 
    .Where(x => SqlMethods.DateDiffDay(x.RXS_OrderDate, DateTime.Now) >= 7 && 
       SqlMethods.DateDiffDay(x.RXS_OrderDate, DateTime.Now) < 14) 
group j by new { j.RXS_ACCN, j.RXS_OrderDate.Date } into g 
select new OrderOverViewModel 
{ 
    Quantity = g.Count(), 
    ACCN = g.Key.RXS_ACCN, 
    OrderDate = g.Key.Date 
}; 

更新版（LINQ到實體）：

from j in context.RXS_RxJobs 
    .Where(x => SqlFunctions.DateDiff("wk", x.RXS_OrderDate, DateTime.Now) == 1) 
group j by new { 
    j.RXS_ACCN, 
    Date = EntityFunctions.TruncateTime(j.RXS_OrderDate).Value 
} into g 
select new OrderOverViewModel { 
    Quantity = g.Count(), 
    ACCN = g.Key.RXS_ACCN, 
    OrderDate = g.Key.Date 
}; 

Answer 2

var viewModels = from job in ObjectContext.RXS_RxJobs 
where SqlFunctions.DateDiff("Day", RXS_OrderDate,DateTime.Now) == 1 
group job by new { RXS_ACCN, OrderDate} into jobGroup 
select new OrderOverViewModel 
{ 
    Quantity = jobGroup.Count(), 
    ACCN = jobGroup.Key.RXS_ACCN, 
    OrderDate = jobGroup.Key.OrderDate 
} ;