組與存儲庫和實體框架

Question

我有這樣的實體框架代碼：

repository.GetObjectQuery(Of COUNL1)(). 
    Where(Function(a) a.CDATE >= '2012/01/01' And 
      a.CDATE <= '2012/12/01' And 
      COID = 88). 
    GroupBy(Function(m) m.CDATE). 
    Select(Function(n) New PointXY With { 
     .Y = n.Sum(Function(k) k.TOTALVH), 
     .X = n.First().CDATE}). 
    ToList() 

此錯誤accoured：

Only parameterless constructors and initializers are supported in LINQ to Entities. 

描述： 我想組由CDATE和sum TOTALVH，並把它在PointXY類中像這樣

PointXY {.Y = Sum(TOTALVH), .X = CDATE}) 

sql查詢：

SELECT  SUM(TOTALVH) AS EXPR1, CDATE 
FROM   COUNL1 
WHERE  (CDATE >= '2012/01/01') AND (CDATE <= '2012/12/01') AND (COID = 88) 
GROUP BY CDATE 

請幫助我，謝謝大家。

Answer 1

的錯誤信息是：

Only parameterless constructors and initializers are supported in LINQ to Entities.

所以去檢查你的PointXY類。

如果它沒有無參數構造函數...只需添加一個！

Public Sub New() 
End Sub