I agree, but I would add that the hardest part of SQL is rarely the syntax itself. More often, it is understanding grain, cardinality, and join explosion. Many junior analysts know how to use JOIN and GROUP BY, yet still produce incorrect KPIs due to silent row duplication.
Absolutely agree. SQL syntax is often the easier part to learn. Understanding data grain, cardinality, and how joins can unintentionally duplicate rows is where many beginners struggle. It's one of the reasons I encourage learners to work with real datasets and business scenarios rather than focusing only on query writing. Thanks for highlighting this important point.
Alessandro Pieraccini
I agree, but I would add that the hardest part of SQL is rarely the syntax itself. More often, it is understanding grain, cardinality, and join explosion. Many junior analysts know how to use JOIN and GROUP BY, yet still produce incorrect KPIs due to silent row duplication.