SQL — Prerequisites
What You Need Before Starting
SQL is one of the more accessible technologies to start with — it doesn't require deep prior technical background, and many people learn it as their first genuinely "programming-adjacent" skill. A few things make the learning curve much smoother.
1. Basic spreadsheet familiarity (recommended, not required)
If you've used Excel or Google Sheets — sorting, filtering, basic formulas like SUM or AVERAGE — you already have real intuition to build on. A SQL table is conceptually similar to a spreadsheet tab: rows and columns, with SQL giving you a much more powerful and precise way to filter, combine, and summarize that data than spreadsheet formulas can. If spreadsheets are unfamiliar too, that's fine — just expect the first week to include building this basic tabular-data intuition alongside SQL syntax itself.
2. Comfort with basic logical thinking (AND/OR/NOT)
SQL's WHERE clause logic (AND, OR, NOT, combined with parentheses for precedence) maps directly onto ordinary logical reasoning — if you've ever reasoned through "I want A and B, but not C," you already have the intuition SQL's filtering logic is built on. This isn't a hard prerequisite, but if boolean logic feels genuinely unfamiliar, a little extra time on the Fundamentals tab's WHERE-clause material specifically will pay off across everything that follows.
3. A place to actually practice — required, not optional reading
You cannot learn SQL by reading queries alone; you need to run them, see real results, and — critically — make mistakes and see exactly what breaks. Reasonable starting points, easiest first:
docker run -d -p 5432:5432 -e POSTGRES_PASSWORD=pass postgres) — closer to what you'll actually use professionally, worth moving to once basic syntax is comfortable
4. Basic command-line comfort (helpful, not a hard blocker)
Many SQL tools have a GUI (DBeaver, pgAdmin, MySQL Workbench, TablePlus) that don't require command-line usage at all, so this isn't strictly required to start — but if you're comfortable with a terminal, being able to connect via psql or mysql command-line clients directly is a useful skill that shows up in real professional environments, worth building alongside SQL itself rather than treating GUI tools as the only path.
5. What you do *not* need yet
ROWNUM, MySQL vs. PostgreSQL CTE behavior) flagged explicitly where they matter, rather than assuming deep prior expertise in any one engine
Quick self-check
Given a spreadsheet-style table of orders (customer name, amount, date), can you describe in plain English what "show me the total amount spent by each customer, but only customers who spent more than $500 total" is actually asking for, step by step? If yes — even without knowing the SQL syntax yet — you already have the logical structure the Fundamentals tab will teach you to express in actual SQL (this is exactly a GROUP BY + HAVING query). If describing that request feels hard, spend a little time on prerequisite #2 first; the SQL syntax will be much easier to absorb once the underlying logical structure is comfortable.