date issue due to datediff function in between - sql

Question

I have following query:
SELECT
datediff(d, 0, sauda_date),
Scrip_Code,
SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty ELSE 0 END) AS BuyQty,
SUM(CASE WHEN Buy_sell = 1 THEN Market_Rate ELSE 0 END) AS BuyRate,
SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty * Market_Rate ELSE 0 END) AS BuyAmount,
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty ELSE 0 END) AS SellQty,
SUM(CASE WHEN Buy_sell = 2 THEN Market_Rate ELSE 0 END) AS SellRate,
(CASE WHEN SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty ELSE 0 END) >
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty ELSE 0 END) THEN 'BF'
ELSE 'BT' END ) as TradeType,
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty * Market_Rate ELSE 0 END) AS SellAmount,
SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty ELSE 0 END) -
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty ELSE 0 END) as NETQTY,
SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty * Market_Rate ELSE 0 END) -
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty * Market_Rate ELSE 0 END)as NetAmt,
SUM(CASE WHEN Buy_sell = 2 THEN Trade_Qty * Market_Rate ELSE 0 END) -
SUM(CASE WHEN Buy_sell = 1 THEN Trade_Qty * Market_Rate ELSE 0 END) as PNLAmt
FROM tradeFile
where Inst_Type = 'FUTIDX'
OR Inst_Type='FUTSTK'
and Sauda_Date = convert(datetime,'1 Mar 2013')
group by Scrip_Code, ExpiryDate, datediff(d,0,sauda_date)
Result:
This query is for taking sum of Buy_Qty,Sell_Qty datewise.[With ref to this quest:not able to get individual date in query result
But as we can see datediff(d,0,sauda_date) column (i.e. first column) is giving me some result, but i wanted to add sauda_date also in this result as a date.
what changes i should make in this query.
I tried it by adding directly sauda_date in query but it gives me error.
Please guid me.

Answer 1

If you use a GROUP BY in your query then (in case of T-SQL) in the field's part of a query you can use only fields from GROUP BY or aggregate functions (SUM, COUNT,....). So you can't add just sauda_date. You should add it with aggregate function. For example MIN(sauda_date). OR you can add it to GROUP BY part.

Answer 2

Not sure with your result requirement..
simply adding sauda_date in select list should not give error if you includ it in group by list, i have tried belwo and its working.
Select datediff(d,0,f.Date),
sum(f.price),
f.OrderID,
f.Date
from test f
group by f.Date,OrderID,datediff(d,0,f.Date)
Else
you can use self join to get only sauda date joining main result on your key column