Subject Re: [firebird-support] 'Invalid expression' error in GROUP BY when field based on a SQL statement is used in SELECT field list
Author Arno Brinkman
Post date 2016-01-18T09:10:52Z
May be this is what you want:
 
SELECT
  ReceiptID,
  (SELECT FIRST 1 S.Service
   FROM ReceiptLine RLF JOIN Service S ON (S.ServiceID = RLF.ServiceID)
   WHERE RLF.ReceiptLineID = MIN(RL.ReceiptLineID)
  ) AS Service,
  SUM(Qty*Cost) Price 
FROM
  ReceiptLine RL
GROUP BY
  ReceiptID
 
Regards,
Arno Brinkman
ABVisie
 
 
 
 
Sent: Monday, January 18, 2016 9:50 AM
Subject: [firebird-support] 'Invalid expression' error in GROUP BY when field based on a SQL statement is used in SELECT field list
 


This error: "Dynamic SQL Error SQL error code = -104 Invalid expression in the select list (not contained in either an aggregate function or the GROUP BY clause)" is returned by the following SQL:


SELECT
           ReceiptID,
           (
            SELECT FIRST 1 S.Service FROM Service S
            WHERE (S.ServiceID = RL.ServiceID)
            ORDER BY RL.ReceiptLineID
            ) AS Service,
           SUM(Qty*Cost) Price 
        FROM ReceiptLine RL    
        GROUP BY ReceiptID, Service



Additional information:
The table ReceiptLine is a detail (as in master-detail) table that stores the line items relating to a purchase, with the fields ReceiptID and ServiceID being foreign keys. The Service table stores product/service names.

Using the ReceiptLine and Service tables, the SQL needs to provide the total of each receipt with only the first service name from the set of line items.

Is there an alternative way, using SQL only, to achieve the desired result?