Question

有关如何将此Linq to Entities（VB.Net）查询更改为Group by L2_ID列的任何建议，并将计算的列diff聚合为该组的Sum。

由于

From l In Level3s 
Join a In BaseLines On l.L3_ID Equals a.L3_ID 
Order By l.L2_ID 
Select Activity = l.L2_ID, Diff = (a.ACT_DATE.Day - l.ACT_DATE.Day)

Answer 1

尝试连续两次查询：

Dim q = From l In context.Level3s _
        Join a In contexts.BaseLines On l.L3_ID Equals a.L3_ID _
        Order By l.L2_ID _
        Select Activity = l.L2_ID, Diff = (a.ACT_DATE.Day - l.ACT_DATE.Day)
Dim q1 = From el In q _
         Group By Key = el.Activity Into G = Sum(el.Diff) _
         Select Key, G

在计算列上分组并汇总

1 个答案: