加入、分组和计数 sql 到 linq 的转换

Question

查询：

SELECT COUNT(*) as Avalied
FROM LeaveMaster as lm
JOIN LeaveSubsidary as ls 
ON lm.TransMasterId = ls.TransMasterId
WHERE lm.SystemCode = 'abc123' AND lm.EmployeeCode = '0014' AND lm.Status ='Approved'
Group by ls.Leave_Type

如何将上述 sql 查询转换为 linq？谢谢:)

编辑：

from p in db.PY_LeaveTransactionMasterTAB.AsEnumerable()
join e in db.PY_LeaveTransactionSubsidaryTAB.AsEnumerable() on p.LV_TransMasterId equals e.LV_TransMasterId into grp
where p.SystemCode == SysCode && p.EmployeeCode == EmpCode && p.Status == "Approved"
group grp by e.Leave_Type // This line is invalid Why?

以上是我到目前为止尝试过的，为什么我不能e.Leave_Type或者group grp by e.Leave_Type的正确方法是什么？

Answer 1

你可以试试这个：

(from p in db.PY_LeaveTransactionMasterTAB
join e in db.PY_LeaveTransactionSubsidaryTAB on p.LV_TransMasterId equals e.LV_TransMasterId 
where p.SystemCode == SysCode && p.EmployeeCode == EmpCode && p.Status == "Approved"
group new {p,e} by new {e.Leave_Type } into gr
select new 
{
   Leave_Type = gr.Key.Leave_Type ,
   Count = gr.Count()
}).ToList();