SQL Learning Roadmap

A recommended order for learning SQL, with the modules of this course mapped to each stage and a rough time estimate at 1–2 hours per day.

Concept

A recommended order for learning SQL, with the modules of this course mapped to each stage and a rough time estimate at 1–2 hours per day.

Why It Matters

Skipping fundamentals (NULL, GROUP BY, joins) causes confusion later with window functions and optimization. Following a sequence builds each skill on solid ground.

Syntax

Beginner
   ↓
SQL Fundamentals ................ Modules 1–5    (databases, keys, data types, constraints)        ~1 week
   ↓
SELECT & Filtering .............. Modules 6–9    (INSERT/UPDATE/DELETE, SELECT, WHERE, ORDER BY)   ~1 week
   ↓
Functions ....................... Module 10      (string, numeric, date, NULL, CASE)                ~4 days
   ↓
GROUP BY ........................ Modules 11–12  (aggregates, GROUP BY, HAVING)                     ~4 days
   ↓
JOIN ............................ Module 13      (all join types, fan-out)                          ~1 week
   ↓
Subqueries ...................... Modules 14–15  (subqueries, EXISTS, set operations)               ~5 days
   ↓
CTEs ............................ Module 16      (WITH, recursive CTEs)                             ~3 days
   ↓
Window Functions ................ Module 17      (ranking, LAG/LEAD, running totals)               ~1 week
   ↓
Transactions .................... Modules 21–22  (ACID, isolation, locking)                        ~5 days
   ↓
Indexes ......................... Modules 18–19  (views, indexes)                                  ~5 days
   ↓
Query Optimization .............. Module 20      (execution p
…

Example

Suggested weekly plan for a 12-week program:

Sample database created with all constraints Level 1 problems (1–15) solved

Level 2 problems 16–23, monthly report query Level 2 problems 24–29, join cheat sheet in your own words Level 3 problems 30–41

Level 3 problem 42, window-function exercises Index experiments with EXPLAIN on 1M generated rows

Concurrency experiments with two sessions; normalization exercise

Procedure, trigger, and role setup for Project 4 Project 1 or 2 complete Modules 35–36, 44

Project 7 (automotive) or Project 3 complete Level 4 problems 43–51, final quiz, checklist

Expected Result

By the end of the roadmap you can design a schema, write correct analytical queries, reason about performance and concurrency, and discuss SQL confidently in interviews.

Common Mistakes

Jumping to window functions before being fluent with GROUP BY and joins.

Reading without typing and running queries.

Never working with data large enough to see performance effects.

Best Practices

Practice daily, even 30 minutes.

Keep a personal "SQL patterns" notebook.

Revisit earlier modules after finishing projects — they will make more sense.

Interview Relevance

The roadmap mirrors what interviewers expect by level: junior (weeks 1–6), mid-level (weeks 7–10), senior (weeks 11–12 plus real experience).

Practice Questions

Which stage are you at now? List the next three modules you will study.

Generate one million rows with generate_series (PostgreSQL) or a recursive CTE and measure a query before and after adding an index.