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About this course
This course drills the SQL that analysts actually write: pulling the right rows, joining tables without duplicating them, aggregating at the correct grain, and ranking or comparing across periods. You'll work through multiple-choice questions on joins, GROUP BY and HAVING, subqueries and CTEs, window functions, date handling, and the NULL behaviour that quietly ruins results. It's for aspiring and working analysts, and for anyone facing a SQL round in an interview.
Why practice SQL
Reading a query is easy; writing the right one from a vague business question is the actual job. Most SQL interviews and take-homes test exactly that — whether you reach for a LEFT JOIN or an inner one, whether you filter in WHERE or HAVING. Answering questions forces the choice, and the explanation shows you what the wrong version would have returned.
How this course works
- Short MCQ sessions you can finish in a coffee break
- Every answer comes with an explanation of why it's right and why the alternatives fail
- Scenario questions that hand you a schema and a business question to answer
- Difficulty ramps from single-table SELECTs to multi-CTE analysis
What you'll walk away with
Fluency with the query patterns that come up daily, a reliable instinct for when results look wrong because of a join or a NULL, and enough repetition that window functions stop feeling like a special occasion.
Data Analyst series
