Running Total Of Daily Sales

Question

How do I get the running total of sales per day in PostgreSQL?

Accepted Answer

```sql
SELECT 
    created_at::date AS sale_date, 
    SUM(price) AS daily_total,
    SUM(SUM(price)) OVER (ORDER BY created_at::date) AS running_total
FROM orders
GROUP BY created_at::date;
```

This query calculates the daily sum of the "price" column from the "orders" table and uses the `SUM()` window function to compute a cumulative running total ordered by the date.