Cannot perform an aggregate function on an expression containing an aggregate or a subquery.

Question

I am getting "Cannot perform an aggregate function on an expression containing an aggregate or a subquery." error by executing below query, I need to calculate the percentage. Can you please help me on this by modifying the query.
select oe2.OrdSourceID,Count(oe2.OrdSourceID) as TotalOrders,
Percentage = Count(oe2.OrdSourceID) * 100.0 / SUM(Count(oe2.OrdSourceID))
  from OeOrders Oe 
  iNNER JOIN OeOrders2 AS oe2
       ON Oe.OrderID = oe2.OrderID
where
Oe.ProviderID = 'JOHN' and Oe.OrderDateTime between '10/07/2014' and '10/15/2014' and oe2.OrdSourceID is not null
  AND Oe.[Status] NOT IN ( 'CANCEL', 'CANC', 'CNC', 'UNVER', 'UNV' )
Group by oe2.OrdSourceID
Thanks..
Diddi

Answer 1

Hi,
please check this general solution using CTE. If you need a specific query help then pls post your DDL+DML :-) I hope you can get the idea from this example.
/************************************************ DDL+DML */
-- DDL
create table T (Num int, Name nvarchar(10))
-- DML
insert T values (1,'a'),(2,'a'),(3,'s'),(22,'s')
GO
/************************************************ Testing and solution */
select SUM(count(*))
from T
GO
--Msg 130, Level 15, State 1, Line 7
--Cannot perform an aggregate function on an expression containing an aggregate or a subquery.
;with MyCTE as (select count(*) C, Name from T group by Name)
--select * from MyCTE
select SUM(C), Name
from MyCTE
group by Name
GO
/************************************************ Clean */
drop table T
GO
  Ronen Ariely
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