SQL & Database Design — PostgreSQL & MySQL
The skill every backend, data and analytics interview tests — done properly.
Lifetime access · Certificate included · US timezone sessions
The 30-minute demo is free, needs no card, and carries no obligation. If we aren't the right fit for your goals, we'll tell you.
- Tutorials finished, but nothing deployed you can show
- A resume that lists coursework instead of shipped work
- Freezing when an interviewer asks you to explain a decision
- Unsure which skills US employers actually screen for
- 4 deployed projects with real source code
- A US-format resume built around what you shipped
- Mock interviews with written feedback, before the real one
- A clear path toward Data Analyst
Who this course is for
This course was designed around specific situations. If one of these sounds like you, you're in the right place.
What you'll learn
By the end of this course you will be able to do each of the following in real projects, not just in exercises.
Write complex joins, subqueries and window functions with confidence
Design normalised schemas that survive real-world change
Read execution plans and fix slow queries with the right index
Use transactions and isolation levels correctly under concurrency
Answer the SQL questions that appear in data and backend interviews
Your learning roadmap
The course runs in phases. Each one ends with a concrete milestone, so you always know whether you're on track.
- 1
Query Fundamentals
Weeks 1–2Focus: Getting data out
What you'll do
- Filter, sort, group and aggregate confidently
- Master every join type and know when each applies
- Write subqueries and common table expressions
- Handle NULLs without silent bugs
MilestoneAnswer 50 real analytical questions against a production-shaped dataset.
- 2
Schema Design
Weeks 3–4Focus: Structuring data well
What you'll do
- Apply normalisation up to 3NF and know when to denormalise
- Model one-to-many and many-to-many relationships
- Enforce integrity with constraints, keys and checks
- Plan migrations that do not lock production tables
MilestoneDesign and implement a complete schema for a multi-feature application.
- 3
Performance & Advanced SQL
Week 5Focus: Making it fast
What you'll do
- Read EXPLAIN ANALYZE output and act on it
- Choose between B-tree, hash, GIN and composite indexes
- Use window functions for ranking, running totals and gaps
- Cache hot reads with Redis
MilestoneTake a deliberately slow query from seconds to milliseconds.
- 4
Production & Interviews
Week 6Focus: Real-world usage
What you'll do
- Use transactions, isolation levels and locking correctly
- Write stored procedures, triggers and views appropriately
- Handle backups, replication and recovery basics
- Solve timed SQL interview problems under pressure
MilestonePass a mock SQL screen modelled on a US data-team interview.
Everything you'll cover
A map of the whole curriculum at a glance — every major area and the topics inside it.
- SELECT & filtering
- Joins
- Subqueries
- CTEs
- Set operations
- GROUP BY
- HAVING
- Window functions
- Rollups
- Normalisation
- Keys & constraints
- Relationships
- ER modelling
- Indexes
- EXPLAIN plans
- Query rewriting
- Partitioning
- Caching
- ACID
- Isolation levels
- Locking
- Deadlocks
- Migrations
- Backups
- Replication
- Monitoring
Week-by-week syllabus
A structured breakdown of exactly what you'll cover, week by week.
Projects you'll build
You finish with a portfolio of deployed work — the thing hiring managers actually look at.
E-Commerce Analytics Schema
Design and query a full retail schema covering orders, inventory and customers.
Query Optimisation Lab
Diagnose and fix ten deliberately pathological queries using execution plans.
Cohort & Retention Analysis
Window-function-driven analysis producing retention curves and cohort tables.
Interview Problem Set
Fifty timed SQL problems mirroring real US data-team screens, with solution walkthroughs.
Where this course can take you
Typical roles this course prepares you for, with current US market compensation ranges.
| Role | US salary range | Demand |
|---|---|---|
| Data Analyst | $70,000 – $105,000 | Very high |
| Database Developer | $90,000 – $135,000 | High |
| Data Engineer | $110,000 – $160,000 | Very high |
| Backend Engineer | $100,000 – $150,000 | Very high |
Salary ranges are indicative market figures for reference, not guarantees of employment or compensation.
Prerequisites
- No prior database experience required
- Comfort with basic spreadsheet logic helps but is not necessary
- Any operating system — setup is covered for all three
Tools you'll use
Frequently asked questions
Should I learn PostgreSQL or MySQL?
The course teaches both because the core SQL is shared. PostgreSQL has richer features and is the more common choice in modern US startups and data teams; MySQL remains widespread in established web applications. Learning the differences takes days once you know one well.
How important is SQL for data analyst and data engineer jobs?
It is the single most-tested skill in those interviews. Most US data analyst screens include a timed SQL assessment involving joins, aggregation and window functions. Strong SQL frequently matters more than knowing a specific BI tool.
What are window functions and why do they matter?
Window functions compute values across a set of rows related to the current row without collapsing them into a single group. They power running totals, rankings, moving averages and period-over-period comparisons — and they appear in nearly every intermediate SQL interview.
Is six weeks enough to become good at SQL?
For the skills interviews test, yes. Six weeks at 10–12 hours per week covers querying, design and optimisation with substantial hands-on practice. Depth in database administration takes longer, and the course points you at that path.
Do I need to install anything complicated?
No. Week one includes guided setup for Windows, macOS and Linux, plus a browser-based option so you can start querying immediately if local installation gives you trouble.