如何使用group by子句将SQL select count转换为LINQ？

Question

如何将以下SQL查询转换为LINQ？

SELECT [EmpUserName],[LeaveTypeName],Count([NoOfDays]) as 'Count' 
FROM [NSL.LeaveSystem02].[dbo].[ProcessedCPLeaves] 
GROUP BY [LeaveTypeName],[EmpUserName],[ProcessingDate] 

请帮忙。

感谢

Answer 1

以下是方法的语法

ProcessedCPLeaves 
.GroupBy(item => new { 
       LeaveTypeName = item.LeaveTypeName, 
       EmpUserName = item.EmpUserName, 
       ProcessingDate = item.ProcessingDate 
}).Select (grouping => new { 
       EmpUserName =grouping.Key.EmpUserName, 
       LeaveTypeName = grouping.Key.LeaveTypeName, 
       TotalCount= grouping.Count() 
}); 

Answer 2

这给一个尝试，

from a in ProcessedCPLeaves 
group a by new 
    { 
     LeaveTypeName = a.LeaveTypeName, 
     EmpUserName = a.EmpUserName, 
     ProcessingDate = a.ProcessingDate 
    } into g 
select new 
    { 
     EmpUserName = g.Key.EmpUserName 
     LeaveTypeName = g.Key.LeaveTypeName 
     TotalCount = g.Count() 
    }