The journey of every round

The seller claims their 30-day return policy is firm. Does that override my legal rights?

I changed my mind about an online purchase. How long do I have to return it?

The product description said waterproof but the item leaks. What can I do?

I bought something on sale. Do I still have the same rights as full-price goods?

A second-hand car broke down 2 weeks after I bought it from a dealer. What are my rights?

The retailer is charging me a restocking fee for a return. Is that allowed?

I paid for a service that wasn't completed. Am I entitled to my money back?

The seller says the warranty only covers manufacturing defects. Does that limit my statutory rights?

Goods arrived damaged. Who is responsible — me, the courier, or the seller?

I bought a phone 6 months ago and it's developed a fault. Can I get a repair?

The shop says I cannot return because I lost the receipt. Is that legal?

I bought a sofa that's a different colour than what I saw on the website. What are my rights?

I bought online but didn't open the box for 30 days. Can I still return it?

The retailer is offering a credit note instead of a refund. Can I insist on cash?

I bought a kettle that broke after 3 weeks. Am I entitled to a refund under UK consumer law?

Find the date with the highest number of new signups in a users table.

Use HAVING to filter aggregate results: orders with more than 5 line items.

Write a SQL query joining 4 tables (customers, orders, line_items, products) to produce a customer-order-product report.

Find products in the top 10 percent by revenue using NTILE.

Calculate the gap in days between consecutive logins per user using LAG.

Use EXISTS to find customers with at least one cancelled order.

Find the median salary in each department using window functions.

Write a recursive CTE to walk an employee-manager hierarchy from any starting employee.

Use UNION to combine current_employees and former_employees, marking source.