The language that runs behind almost every app. Query and join real tables, understand the injection that leaks whole databases, and make a slow query 300 times faster.
3 units, about 3 hours. Free.
Query related tables with SELECT, WHERE, GROUP BY and JOIN, and explain why data is split across tables.
2Reproduce a SQL injection attack and prevent it with parameterised queries.
3Measure the speed-up an index gives, explain the tree behind it, and state what indexes cost.