SQL
Calculate Running Totals (Cumulative Sum) in SQL
Understand how to compute cumulative sums or running totals over a set of rows in SQL, essential for financial analysis, sales trends, and inventory tracking.
SELECT
order_date,
daily_sales,
SUM(daily_sales) OVER (ORDER BY order_date ASC) AS running_total_sales
FROM
daily_sales_summary
ORDER BY
order_date;
How it works: This snippet calculates a running total (cumulative sum) of daily sales. The `SUM(daily_sales) OVER (ORDER BY order_date ASC)` is a window function that computes the sum of `daily_sales` for all rows from the beginning of the result set up to the current row, based on the `order_date`. This is highly useful for tracking cumulative metrics like total revenue over time or inventory levels.