LINQ RowNumber，Aggregate（Sum）和GroupBy

我有一个SQL代码像;LINQ RowNumber，Aggregate（Sum）和GroupBy

Select GroupName, sum(LineAmount) as Total, WeekNumber, 
    ROW_NUMBER() over (partition by WeekNumber order by sum(LineAmount) desc) as RowNum 
from 
    Invoices 
where 
    month(InvoiceDate)=month(getdate()) 
group by 
    GroupName,WeekNumber

我想将其转换为LINQ，但没有运气。我正在使用LINQ来对象。任何帮助，将不胜感激。 TIA

编辑：这是一些示例数据和预期结果。

public class Invoice 
{ 
    public string GroupName { get; set; } 
    public int LineAmount { get; set; } 
    public int WeekNum { get; set; } 
} 

    List<Invoice> theData = new List<Invoice>(); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 1, WeekNum = 1}); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 2, WeekNum = 1 }); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 3, WeekNum = 1 }); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 2, WeekNum = 2 }); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 3, WeekNum = 2 }); 
    theData.Add(new Invoice { GroupName = "A", LineAmount = 4, WeekNum = 2 }); 
    theData.Add(new Invoice { GroupName = "B", LineAmount = 4, WeekNum = 1 }); 
    theData.Add(new Invoice { GroupName = "B", LineAmount = 3, WeekNum = 1 }); 
    theData.Add(new Invoice { GroupName = "B", LineAmount = 7, WeekNum = 2 }); 
    theData.Add(new Invoice { GroupName = "B", LineAmount = 6, WeekNum = 2 }); 
    theData.Add(new Invoice { GroupName = "B", LineAmount = 5, WeekNum = 2 });

enter image description here

我已删除“其中”从我第一次查询其此刻不存在问题。

来源

2012-08-07 bsaglamtimur

theData 
.GroupBy(g => new {g.GroupName, g.WeekNum}, (key, gg) => new {key.GroupName, key.WeekNum, Total = gg.Sum(g => g.LineAmount)}) 
.GroupBy(g => g.WeekNum, (weekNum, gg) => gg.OrderByDescending(g => g.Total).Select((g,i) => new {g.GroupName, g.Total, g.WeekNum, RowNum = i})) 
.SelectMany(g => g)

来源

2012-08-08 07:11:26

'RowNum = i'应该是'RowNum = i + 1'来给出预期的结果。 – sloth 2012-08-08 07:18:33

谢谢Serg，你的解决方案给了我预期的结果。我已经找到了一个解决方案。我不知道哪一个表现最好！任何想法将不胜感激。 – bsaglamtimur 2012-08-08 08:20:41

@bsaglamtimur他们或多或少相同，而选择是个人喜好和可读性的问题。就我而言，我不喜欢嵌套查询。 – 2012-08-08 08:30:49

您还没有指定您需要的语言。这是在C＃代码

int index = 0; 
var filteredInvoices = (from i in invoices 
where i.InvoiceDate.Month == DateTime.Now().Month 
group i by new { i.GroupName, i.WeekNumber } 
into ig 
select new {i.GroupName, Total = ig.Sum(i => i.LineAmount), i.WeekNumber, RowNum = ++index}).OrderByDescending(n => n.Total);

filteredInvoices应该有你想要的结果。另外我假设i.InvoiceDate是DateTime类型的。

来源

2012-08-07 20:27:55

我已编辑我的问题。你能否根据我的样本数据来回顾你的答案。 – bsaglamtimur 2012-08-08 06:40:40

Serg Rogovtsev答案给了我预期的结果。下面的代码就是我所做的。不知道哪个性能更好，但结果相同。

(theData.GroupBy(f => new { f.GroupName, f.WeekNum}) 
       .Select(r => new {r.Key.WeekNum, r.Key.GroupName, Total = r.Sum(f => f.LineAmount)})) 
       .GroupBy(r => new {r.WeekNum}).SelectMany(
        g => 
        g.OrderByDescending(f => f.Total).Select(
         (f, index) => new { f.GroupName, f.Total, f.WeekNum, Ix = index + 1 }))

来源

2012-08-08 08:16:12 bsaglamtimur

LINQ RowNumber，Aggregate（Sum）和GroupBy

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