SQL-query om financiële jaargegevens op jaarbasis op te halen

SELECT
   CASE WHEN MONTH(service_date)>=7 THEN
          concat(YEAR(service_date), '-',YEAR(service_date)+1)
   ELSE concat(YEAR(service_date)-1,'-', YEAR(service_date)) END AS financial_year,
   SUM(invoice_amount)
FROM mytable
GROUP BY financial_year

die o/p produceren zoals hieronder

financial_year   invoice_amount
2007-2008        10000.00
2008-2009        15000.00
2009-2010        20000.00