Learn MySQL Visually
Understand how MySQL works under the hood. Visualize B-trees, decode EXPLAIN outputs, trace query execution, and master optimization techniques.
Beginner
Introduction to MySQL
What is MySQL? Learn query types (DDL/DML/DCL), InnoDB storage, page structure, and how reads/writes work.
SQL Basics
Master the fundamentals: SELECT, WHERE, ORDER BY, LIMIT. Learn filtering with AND/OR, IN, BETWEEN, LIKE, and pattern matching.
Data Types & NULLs
Understand MySQL data types and master NULL semantics. Interactive quizzes reveal common NULL traps like COUNT(*) vs COUNT(col).
B-Tree Indexing
See how MySQL uses B-trees to find data efficiently. Compare indexed lookups vs full table scans.
Execution Order
See the logical order MySQL processes query clauses. FROM first, SELECT near the end!
JOIN Types
Visualize how INNER, LEFT, RIGHT, and CROSS JOINs combine tables. See which rows match and which get NULL.
Intermediate
Join Types & Patterns
Master INNER, LEFT, RIGHT, CROSS, SELF joins plus semi/anti-join patterns with animated visualizations
Cardinality & Keys
Understand PK/FK constraints, UNIQUE, and relationship types (1:1, 1:N, M:N) with constraint demos
EXPLAIN Analysis
Decode MySQL EXPLAIN output. Understand access types, key usage, and performance implications.
WHERE vs HAVING
Understand the critical difference: WHERE filters rows BEFORE grouping, HAVING filters AFTER. See it in action!
Index Types
Compare B-Tree, Hash, Full-Text, and Spatial indexes. Learn when to use each type.
Normalization
Learn 1NF, 2NF, 3NF and when to denormalize. See how to eliminate data redundancy.
Data Layout & Index Structure
Understand clustered indexes, secondary indexes, covering indexes, and how data is stored on disk
Advanced
Subqueries
See how nested queries execute. Compare correlated vs non-correlated subqueries and their performance.
Query Optimization
Learn to identify and fix slow queries. See anti-patterns and their optimized alternatives.
Transactions & Locking
Understand ACID properties, isolation levels, and how MySQL handles concurrent access.
CTEs (Common Table Expressions)
Master WITH clauses from basics to recursive CTEs. Learn to traverse hierarchies, simplify complex queries, and write readable SQL.
Window Functions
Master ROW_NUMBER, RANK, LEAD/LAG, running totals, and window frames with animated visualizations
InnoDB Internals
Understand buffer pool, redo/undo logs, change buffer, and crash recovery mechanisms
Sample Dataset
All visualizations use this static dataset. Queries run against simulated data:
employees
id, name, department_id, salary, hire_date
20 rows
departments
id, name, budget
5 rows
orders
id, employee_id, product, amount, order_date
15 rows