以分钟为单位获得两个日期之间的平均差

Question

我试图让每个插座在几分钟内获得平均接收时间。

我有两份订单和收货订单。

订单

OrderID OutletID OrderDate
1       1        2017-04-10 17:04:41.000

ReceivedOrders

ReceivingID OrderID ReceivingDate
1           1       2017-04-10 17:06:31.000

我已尝试过以下查询，但其重新计算为零作为平均接收时间

SQL查询

SELECT        Outlets.OutletName , avg(datediff(MM, Orders.OrderDate, ReceivedOrders.ReceivingDate)) as Receive
FROM          dbo.Orders INNER JOIN
              dbo.Outlets ON dbo.Orders.OutletID = dbo.Outlets.OutletID INNER JOIN
              dbo.ReceivedOrders ON dbo.Orders.OrderID = dbo.ReceivedOrders.OrderID 
group by dbo.Outlets.OutletName

输出

OutletName Receive
Outlet1    0

Answer 1

使用具有毫秒选项的datediff：

" and _new_technology_value eq '"+techid+"'";