What level of complexity do your SQL queries have in your work?

The level of difficulty of SQL queries in work can vary from simple to quite complex, depending on the task:

• Simple queries: data selection using SELECT, filtering with WHERE, sorting with ORDER BY, limiting the number of rows with LIMIT.
• Medium complexity: joining tables with JOIN (INNER, LEFT, RIGHT), grouping data with GROUP BY, aggregate functions (SUM, COUNT, AVG), subqueries.
• Complex queries: nested subqueries, window functions (ROW_NUMBER(), RANK()), recursive queries, complex filtering and update conditions.

For example, in everyday work, queries often involve multiple JOINs and aggregates to obtain summary data, as well as query optimization for performance improvement.

An example of medium level:

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

Thus, the level of difficulty depends on specific business tasks and data requirements.