Step 2 / Select difficulty SQL
About SQL
Portable queries: joins, grouping, NULLs, and windows.
- Filtering and nulls
- Joins
- Aggregation and grouping
- Subqueries
- Set operations
- Ordering
- Window functions
- Ctes
- Data modification
- Constraints and keys
- Easy: 100 questions
- Medium: 100 questions
- Hard: 100 questions