By Collins Njeru I still remember the first time I ran a query that actually meant something. Not a tutorial exercise with fake names and random numbers , but a real question, against real data, that came back with a real answer. That moment is hard to describe. It feels less like writing code and more like having a conversation with your database. That is what SQL really is. A conversation. And like any conversation, the quality of what you get back depends entirely on how well you frame what you are asking. This article is about learning to ask better questions. We will use a retail sales database - customers, products, sales records, inventory and work through the full range of SQL from the basics all the way to the kind of queries that make a hiring manager lean forward in their chair. The Database We Are Working With Before writing a single query, you need to understand your data. That sounds obvious, but you would be surprised how many people skip this step and wonder why their results look off.…