🛢️ Zero to SQL Expert - Sketchnote Playbook

Struggling to move beyond basic SELECT * queries — copying SQL from Stack Overflow and hoping it works? This guide changes everything. In 12 structured phases, you'll go from understanding your first table to writing recursive CTEs, window functions, and performance-optimized queries that impress at every level — no prior experience needed, no fluff, just real SQL that works.

What's inside this book:

🏗️ SQL foundations that stick SELECT, WHERE, ORDER BY, JOINs, and set operations — built right from day one

📊 Aggregation & grouping mastery COUNT, SUM, AVG + GROUP BY, HAVING, ROLLUP & CUBE for real data summarisation

🔗 Every join type explained INNER, LEFT, RIGHT, FULL OUTER, CROSS, and self joins — with clarity, not confusion

🧠 Subqueries & CTEs unlocked Correlated vs non-correlated, IN/EXISTS/ANY/ALL, recursive CTEs, and best practices

🪟 Window functions — the analytics powerhouse PARTITION BY, ROW_NUMBER, RANK, LEAD, LAG, NTILE, frame specs & QUALIFY

⚡Performance & query optimisation Indexes, execution plans, Scan vs Seek, Nested Loop / Merge / Hash join internals

🛠️ DDL, DML & data manipulation CREATE, ALTER, DROP, INSERT, UPDATE, DELETE + constraints — full database control

🤖 Procedural SQL & automation Stored procedures, UDFs, triggers, dynamic SQL, loops, cursors & error handling

📦 Advanced data structures Views, materialised views, temp tables, JSON parsing & semi-structured data

🔢 Built-in functions & logic String, date/time, numeric functions + CASE, COALESCE, NULLIF, and RegEx