Calculate Running Totals Using Window Functions

SELECT
    sale_date,
    daily_sales,
    SUM(daily_sales) OVER (ORDER BY sale_date) AS running_total_sales
FROM
    daily_sales_report
ORDER BY
    sale_date;

How it works: This query uses a window function to calculate a running total of daily sales. The `SUM(daily_sales) OVER (ORDER BY sale_date)` clause computes the cumulative sum of `daily_sales` for each row, ordered by `sale_date`. As the query progresses through the sorted dates, the sum accumulates the `daily_sales` from the beginning up to the current row, providing a continuous total. This is invaluable for analyzing trends, tracking financial balances, or monitoring progress over time in various business metrics.