Being a beginner, I'm having a hard time coding this particular scenario in SQL Server 2008
As you can see, The SUM column for July 2017 for example is equal to the following: August to Dec 2016 + Jan to July 2017 = 4625
Similarly, the SUM column for August 2017 is equal to the following: Sep to Dec 2016 + Jan to August 2017 = 4625
How can I automate this from month to month?
I understand that this can be done using window functions in SQL Server 2012 onwards but I have to modify this query to work in SQL Server 2008
select year(date), month(date), sum(sum(numbers)) over (order by year(date), month(date) rows between 11 preceding and current row) as prev_12_sum from t group by year(date), month(date) order by min(date);
I appreciate any help I can get.