SQL

Lessons

1. 1

   Relational Database Basics

   Free

   Explain tables, rows, columns, primary keys, foreign keys; set up Postgres or Neon.

   Beginner·25 min
2. 2

   Basic SQL: SELECT, INSERT, UPDATE, DELETE

   Use SELECT/FROM/WHERE/ORDER BY/LIMIT and the basic mutation operations.

   Beginner·35 min
3. 3

   Filtering and Sorting

   Filter with AND/OR/NOT, LIKE, IN, BETWEEN, IS NULL; use DISTINCT.

   Beginner·40 min
4. 4

   JOINs

   Use INNER / LEFT / RIGHT / FULL OUTER JOINs and reason about them visually.

   Intermediate·60 min
5. 5

   GROUP BY and Aggregations

   Use GROUP BY + HAVING + aggregations to summarize data into reports.

   Intermediate·50 min
6. 6

   Subqueries and CTEs

   Use subqueries, EXISTS, CTEs, and recursive CTEs to express complex queries readably.

   Intermediate·55 min
7. 7

   Window Functions

   Use window functions: ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD, running totals.

   Advanced·60 min
8. 8

   Indexes and Query Performance

   Reason about B-tree indexes, composite index direction, and use EXPLAIN ANALYZE.

   Intermediate·55 min
9. 9

   Transactions and ACID

   Use BEGIN/COMMIT/ROLLBACK, understand ACID, pick the right isolation level.

   Intermediate·50 min
10. 10

    Database Design and Normalization

    Apply 1NF/2NF/3NF, decide when to denormalize, draw ER diagrams, pick data types.

    Intermediate·50 min
11. 11

    PostgreSQL-Specific Features

    Use Postgres-specific features: JSONB, arrays, full-text search, pg_trgm, EXPLAIN ANALYZE in depth.

    Advanced·55 min
12. 12

    SQL from Applications

    Use SQL from Node.js, Python, and Prisma with parameterized queries (no SQL injection).

    Intermediate·50 min
13. 13

    Database Performance

    Read EXPLAIN ANALYZE, fix N+1 queries, size connection pools, and run zero-downtime migrations with the expand/contract pattern.

    Intermediate·50 min
14. 14

    Passion Project: Schema + Query Gallery

    Design + ship a realistic Postgres schema (8+ tables, ER diagram, indexes) with a 15-query gallery, hosted on Neon.

    Intermediate·240 min
15. 15

    SQL Job Readiness

    Translate SQL skills into resume bullets + interview answers for backend / data eng / analyst roles.

    Intermediate·30 min