Complete MySQL preparation notes covering queries, joins, schema design, indexing, and interview questions.

flowchart TB
    Start[Start Here 🚀] --> Basics[Database Basics<br/>Architecture, Data Types]
    Basics --> Querying[Querying Data<br/>CRUD, Aggregations, Subqueries]
    Querying --> Joins[SQL Joins<br/>INNER, LEFT, RIGHT, SELF]
    Joins --> Perf[Performance & Transactions<br/>Indexing, ACID, Isolation]
    Perf --> Prog[Programmability<br/>Procedures, Functions, Triggers]
    Prog --> Admin[Administration & Scaling<br/>Users, Backups, Replication]
    Admin --> Interview[Interview Prep<br/>QA, Cheatsheet]

    style Start fill:#7c3aed,color:#fff
    style Basics fill:#3b82f6,color:#fff
    style Querying fill:#059669,color:#fff
    style Joins fill:#06b6d4,color:#fff
    style Perf fill:#f59e0b,color:#fff
    style Prog fill:#ec4899,color:#fff
    style Admin fill:#10b981,color:#fff
    style Interview fill:#ef4444,color:#fff

• Database & RDBMS Basics — What is a database, SQL sublanguages
• MySQL Architecture — Client-server, InnoDB vs MyISAM
• Data Types — Numeric, string, date types
• Keys & Constraints — PK, FK, unique, composite keys, ON DELETE/UPDATE
• Normalization — 1NF, 2NF, 3NF, BCNF with examples

• CRUD Operations — INSERT, SELECT, UPDATE, DELETE
• Aggregations & Functions — COUNT, SUM, AVG, string/date functions
• Subqueries & CTEs — Scalar, correlated, recursive CTEs
• Views — Virtual tables, updatable views, WITH CHECK OPTION
• Window Functions — ROW_NUMBER, RANK, DENSE_RANK, LAG/LEAD
• Set Operations — UNION, INTERSECT, EXCEPT
• CASE & Conditional Logic — CASE WHEN, COALESCE, NULLIF
• Query Execution Order — FROM → WHERE → GROUP BY → HAVING → SELECT
• NULL Handling — NULL traps, comparisons, aggregates, NOT IN

• Joins Overview — Visual guide to all join types
• INNER JOIN — Only matched rows from both tables
• LEFT JOIN — All left rows + matched right
• RIGHT JOIN — All right rows + matched left
• FULL OUTER JOIN — All rows from both (MySQL UNION workaround)
• CROSS JOIN — Every combination (Cartesian product)
• SELF JOIN — Table joined to itself
• Exclusion Joins — Anti-join patterns (NOT IN, NOT EXISTS)
• JOIN Conditions & Pitfalls — Common JOIN mistakes

• Indexing — B-Tree, clustered vs non-clustered, covering indexes
• EXPLAIN & Query Optimization — Reading EXPLAIN, access types
• Performance Optimization — Query, schema, and config optimization
• Transactions & ACID — ACID, COMMIT, ROLLBACK, SAVEPOINT
• Isolation Levels & Deadlocks — 4 levels, anomalies, deadlock prevention
• Locks — Shared/exclusive, row-level vs table-level

• Stored Procedures & Functions — CREATE PROCEDURE, control flow, functions
• Triggers — BEFORE/AFTER INSERT/UPDATE/DELETE

• Users & Privileges — CREATE USER, GRANT/REVOKE, roles
• Backup & Restore — mysqldump, logical vs physical backups
• Replication — Primary → replica, read scaling, binary logs
• Partitioning & Sharding — Table partitioning, horizontal sharding
• JSON & Full-Text Search — JSON columns, FULLTEXT indexes, MATCH AGAINST

• MySQL Interview Prep — Comprehensive Q&A with visuals
• Common Interview Questions — Top interview questions with solutions
• Quick Revision Cheat Sheet — Quick reference for revision
• Quick Reference Summary — Summary of key SQL concepts
• Choosing the Right Join — Decision guide for join types
• JOIN Conditions & Pitfalls — Common JOIN mistakes and fixes