将SQL转换为LINQ：将结果选择到模型

Question

我不熟悉LINQ，任何人都可以帮助我吗？ 在此先感谢。

我的模型：

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

这是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)) 

结果在SSMS：

我想选择的结果填补了模型，如何实现这一目标？ 再次感谢。

Answer 1

使用SqlFunctions.DateDiff方法来获取当前日期和订单日期之间周。您也可以简单地通过DateDateTime对象的属性获取日期的部分日期。查询应该是这样的：

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到实体）：

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 
} ;