Step-by-step solutions to HackerRank's SQL questions, written for beginners. The goal isn't just "here's the query" — it's showing how to think through each problem so the logic actually clicks.

HackerRank is a tech company that focuses on competitive programming challenges for both consumers and businesses, where developers compete by trying to program according to provided specifications.

Profitable Stocks is one of the five questions in the HackerRank SQL (Basic) certification test. It is short. The two things to get right are the comparison and the sort. There is one table of today’s ...