From your first SELECT to joins, grouping and window functions. Every topic with an explanation, examples and an exercise you play right in your browser.
Every learner is different. Pick what fits you.
Module 1
Your first client as a freelance data analyst: the Bonen & Co coffee roastery. You learn to read tables and fetch data with SELECT.
Module 2
Your second client: Rewind, the video store in Mechelen. You learn to find exactly the rows you're looking for with WHERE, comparisons, AND/OR/NOT, IN, BETWEEN, LIKE and NULL.
Module 3
Your third client: the Zomerklank music festival in Hasselt. You learn to sort results with ORDER BY, on several columns, and to remove duplicates with DISTINCT.
Module 4
Your fourth client: De Trapper bike rental in Bruges. You learn to count, add up and average with COUNT, SUM, AVG, MIN and MAX, and to summarise everything per group with GROUP BY and HAVING.
Module 5
Your fifth client: football club FC De Kraaien in Lier. You learn to combine tables with keys and JOIN: INNER, LEFT, RIGHT and FULL, with aliases, across several tables and even a table with itself.
Module 6
Your sixth client: Het Leeslint library in Kortrijk. You learn to query smarter: reshaping text and dates, choosing with CASE, asking questions inside questions with subqueries and EXISTS, and keeping long queries readable with WITH.
Module 7
Your seventh client: Bloem & Boter, a bakery in Leuven. You learn to change data: add rows with INSERT, change them with UPDATE, remove them with DELETE, and work all-or-nothing with transactions.
Module 8
Your eighth client: the Ronde van het Pajottenland, a five-day stage race. You learn window functions: numbering with ROW_NUMBER, ranking with RANK, per group with PARTITION BY, standings with running totals, and combining lists with UNION.