Learn SQL by doing real work.
Learn practical SQL with production-style tables, a browser query lab and real work examples.
From fundamentals to useful work.
Short explanations, runnable examples, quick checks and a hands-on practice set.
SQL SELECT
Choose the columns you want to return from a table.
SQL WHERE
Filter rows so only records that meet a condition are returned.
SQL LIKE
Find text patterns with % and _ wildcards.
SQL ORDER BY
Sort results in ascending or descending order.
SQL Aggregate Functions
Summarize many rows with COUNT, SUM, AVG, MIN and MAX.
SQL GROUP BY
Create one summary row per customer, material, supplier or category.
SQL HAVING
Filter aggregated groups after GROUP BY.
SQL JOINs
Combine related data from two tables using matching keys.
SQL CASE
Create readable categories from business rules inside a query.
SQL Subqueries
Use the result of one query inside another query.
SQL CTEs
Name an intermediate result with WITH to make complex SQL easier to read.
SQL Window Functions
Calculate rankings and running metrics without collapsing detail rows.