Why I need Group by in this simple query? - sql

Question

UPDATE :
-----
the error might be in sum(si.amt_pd) from item table (as there is no relation) :
select SUM(si.amt_pd)amt_pd from [HMIS_REPORTING].HMIS_RPT_ME.dbo.item i
where
is there a work around?
----------
I am trying to run this query. The query just fetches the amount of a month based on some tables. It is just a part of a big query.
select s.sales_Contract_Nbr
, s.Sales_Id
, s.Sale_Dt
, YEAR(s.Sale_Dt) 'YEAR'
, MONTH(s.Sale_Dt) 'MONTH'
, s.Sales_Need_TYpe_Cd
, s.Sales_Status_Cd
, si.Posted
, s.location_Cd
, jan2011 = (
select SUM(si.amt_pd)amt_pd
from [HMIS_REPORTING].HMIS_RPT_ME.dbo.item i
where i.Item_Id = si.Product_Item_ID
and i.Item_Cd <> '*INT'
and convert(varchar(10),SI.Sales_Item_Dt,126) >= '2011-01-01'
and convert(varchar(10),SI.Sales_Item_Dt,126) >= '2011-01-31'
) INTO dbo.#a_acomparision
FROM [HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales S
, [HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales_Item SI
WHERE SI.Sales_Id = S.Sales_Id
and s.Sales_Contract_Nbr in (
select distinct (Sales_Contract_Nbr)
from mountainviewContracts
where Sales_Contract_Nbr <> '')
but I am getting the following error message.
Msg 8120, Level 16, State 1, Line 1
Column 'HMIS_REPORTING.HMIS_RPT_ME.dbo.Sales.Sales_Contract_Nbr' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
I just can't understand why my query should have a group by for sales_contract_nbr and even if I put in the group by clause it tells me that inner query si.Product_item_id and SI.sales_item_dt should also be contained in group by clause.
Please help me out.
Thanks in advance

Answer 1

This is a very subtle problem. However, I think the subquery should be:
select SUM(i.amt_pd)amt_pd from [HMIS_REPORTING].HMIS_RPT_ME.dbo.item i
That is, the alias should be i not si.
What is happening is that the sum in the subquery is on a value in the outer query. So, the SQL compiler assumes an aggregation query. As soon as the first column is found that is not an aggregation, it complains with the message that you have.
By the way, you should use proper join syntax, so you from clause looks like:
FROM [HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales S join
[HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales_Item SI
on SI.Sales_Id = S.Sales_Id

Answer 2

As #Gordon Linoff says, this is almost certainly because the query optimizer is treating this like a SUM operation, normalizing away the subquery for "jan2001".
If the amt_pd column is present in the ITEM table, Gordon's solution is the right one.
If not, you have to add the group by statement, as below.
select s.sales_Contract_Nbr
, s.Sales_Id
, s.Sale_Dt
, YEAR(s.Sale_Dt) 'YEAR'
, MONTH(s.Sale_Dt) 'MONTH'
, s.Sales_Need_TYpe_Cd
, s.Sales_Status_Cd
, si.Posted
, s.location_Cd
, jan2011 = (
select SUM(si.amt_pd)amt_pd
from [HMIS_REPORTING].HMIS_RPT_ME.dbo.item i
where i.Item_Id = si.Product_Item_ID
and i.Item_Cd <> '*INT'
and convert(varchar(10),SI.Sales_Item_Dt,126) >= '2011-01-01'
and convert(varchar(10),SI.Sales_Item_Dt,126) >= '2011-01-31'
) INTO dbo.#a_acomparision
FROM [HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales S
, [HMIS_REPORTING].HMIS_RPT_ME.dbo.Sales_Item SI
WHERE SI.Sales_Id = S.Sales_Id
and s.Sales_Contract_Nbr in (
select distinct (Sales_Contract_Nbr)
from mountainviewContracts
where Sales_Contract_Nbr <> '')
GROUP BY s.sales_Contract_Nbr
, s.Sales_Id
, s.Sale_Dt
, YEAR
, MONTH
, s.Sales_Need_TYpe_Cd
, s.Sales_Status_Cd
, si.Posted
, s.location_Cd