Question

我在linq中写这个查询，我想做这个工作选择新的1和x和y 2-times timespans和数字中的多重播放，例如30

var query = 
    (from c in DB.SabtHoghoghs
     join aa in DB.SabtHesabKarmands on c.KarmandID equals aa.KarmandID
     select new 
        { 
            c.Karmand.FName,
            c.BabatMah,
            x = DB.SabtHesabKarmands.Where(q => q.BabatMah.Year == c.BabatMah.Year &&
                q.BabatMah.Month == c.BabatMah.Month && q.HesabKarmand.HesabKarmandTypeID==1)
                .Sum(aaa => aaa.Tedad * aaa.HesabKarmand.Mablagh),

            y = DB.SabtHesabKarmands.Where(q => q.BabatMah.Year == c.BabatMah.Year &&
                q.BabatMah.Month == c.BabatMah.Month && q.HesabKarmand.HesabKarmandTypeID == 2)
                .Sum(aaa => aaa.Tedad * aaa.HesabKarmand.Mablagh),

            z=y-x   //how to do this(1)

            karkard = (c.Karmand.ExitTime-c.Karmand.EnterTime).Hours *30  //how to do this(2)

        }).Distinct();

Answer 1

我会尽力指导您找到正确的解决方案。定义你的自定义类，不要使用匿名类，如此

class MyClass
{
    public string FName { get; set; }
    public string BabatMah { get; set; }

    public int x { get; set; }
    public int y { get; set; }

    public int z { get { return x - y; }    }

    public int karkard { get; set; }

    // implement Equals and GetHashCode for correct behaviour of Distinct
}

然后只选择没有z的计算值到MyClass

select new MyClass
    { 
        FName = c.Karmand.FName,
        BabatMah = c.BabatMah,
        ...

要解决(c.Karmand.ExitTime-c.Karmand.EnterTime).Hours *30计算，您需要提供有关ORM的更多详细信息。解决方案将取决于。一般的解决方案是将ExitTime和EnterTime提取到MyClass，然后以与计算x - y

相同的方式计算小时差异

Answer 2

在查询中使用let关键字：

var query =
(from c in DB.SabtHoghoghs
join aa in DB.SabtHesabKarmands on c.KarmandID equals aa.KarmandID
let x = DB.SabtHesabKarmands.Where(q => q.BabatMah.Year == c.BabatMah.Year &&
        q.BabatMah.Month == c.BabatMah.Month && q.HesabKarmand.HesabKarmandTypeID == 1)
        .Sum(aaa => aaa.Tedad * aaa.HesabKarmand.Mablagh)
let y = DB.SabtHesabKarmands.Where(q => q.BabatMah.Year == c.BabatMah.Year &&
        q.BabatMah.Month == c.BabatMah.Month && q.HesabKarmand.HesabKarmandTypeID == 2)
        .Sum(aaa => aaa.Tedad * aaa.HesabKarmand.Mablagh)
select new
{
    c.Karmand.FName,
    c.BabatMah,

    X = x,
    Y = y,

    Z = y - x,   //how to do this(1)

    karkard = (c.Karmand.ExitTime - c.Karmand.EnterTime).Hours * 30  //how to do this(2)

}).Distinct();

在linq中加上两个别名

2 个答案: