I'm a software developer at heart and at work. Sometimes when a project ends I get asked "Do you know SQL?" or "Do you do SQL?". I'm puzzled at what exactly are they aiming at. What knowledge or skills would they expect?

Like, sure I can read, understand and write SQL queries. I know what views and stored procedures are. I can distinguish whether something should be done at database level or in business logic (or both, like data validation). I can design and normalize databases from scratch (although I reckon, this is nothing specific to SQL). I've worked both with direct database access from code and via ORMs.

But I've never really optimized SQL queries. I've only recently learned that I shouldn't nest views. I probably make the dumbest mistakes sometimes. I almost alwas have to look up the syntax of something, even if I've done it dozens of times before. I never had to work with locking strategies. I'm not even sure if I fully understand all of the stuff I write.…