Microsoft SQL Server Cumulative Sum


Using the Item Sales Table, we will try to find out how the sales of our items are increasing through dates. To do so we will calculate the Cumulative Sum of total sales per Item order by the sale date.

SELECT item_id, sale_Date 
       SUM(quantity * price) OVER(PARTITION BY item_id ORDER BY sale_Date ROWS BETWEEN UNBOUNDED PRECEDING) AS SalesTotal
  FROM SalesTable