Projects / PRJ-07
Learning
SQL practice for testers
27 SQL questions with solutions from a tester’s point of view: checking data after a test, finding duplicates, orphans and bad records.
27 queries
27SQL questions with solutions
5tables in the schema
Topics covered
- Basics: SELECT, WHERE, ORDER BY, LIMIT, BETWEEN, LIKE, IS NULL
- Aggregates: COUNT, SUM, AVG, MIN, MAX, GROUP BY, HAVING
- Joins: INNER JOIN, LEFT JOIN, joining three tables
- Subqueries and CASE: NOT IN, second highest value, status percentage
- Tester checks: duplicates, missing values, invalid emails, orphan records, negative stock, order total vs item total, business rule violations
Setup
Five tables (users, products, orders, order_items, defects) with small sample data and a few bad records planted on purpose. Every query’s result is saved from a SQLite run. Learning repo; the data is made up.