What level of difficulty did your SQL queries have in your previous project?

In my previous project, my SQL queries ranged from simple selections to medium-complex ones with multiple JOINs, subqueries, and aggregations. For example, I wrote queries to fetch data by joining several tables, filtering by conditions, and grouping results:

SELECT c.name, COUNT(o.id) AS orders_count
FROM customers c
JOIN orders o ON c.id = o.customer_id
WHERE o.status = 'completed'
GROUP BY c.name
ORDER BY orders_count DESC;

Such queries helped in obtaining analytical data and reports. Complex queries with window functions or recursive CTEs were rare and usually executed on the DBA side.