| Beginner | 1 | Introduction & Fundamentals | SQL vs NoSQL, RDBMS, Types of Commands (DDL, DML, DQL, DCL, TCL) |
| Beginner | 2 | Database & Table (DDL) | CREATE, Data Types, Constraints (Primary/Foreign Key), ALTER, TRUNCATE |
| Beginner | 3 | Basic Retrieval (DQL) | SELECT, DISTINCT, WHERE, Operators (AND/OR), ORDER BY, LIMIT, LIKE, BETWEEN |
| Beginner | 4 | Data Modification (DML) | INSERT INTO, UPDATE, DELETE, INSERT INTO SELECT |
| Intermediate | 5 | Aggregate & Grouping | COUNT, SUM, AVG, MIN, MAX, GROUP BY, HAVING, ROLLUP |
| Intermediate | 6 | Joins (Most Important) | INNER, LEFT, RIGHT, FULL OUTER, CROSS, SELF JOIN |
| Intermediate | 7 | Subqueries | Single/Multi-row, Correlated Subquery, Subqueries in SELECT/FROM |
| Intermediate | 8 | Set Operations | UNION, UNION ALL, INTERSECT, EXCEPT / MINUS |
| Intermediate | 9 | Built-in Functions | String (CONCAT, SUBSTRING), Numeric (ROUND), Date (DATEDIFF, CURRENT_DATE) |
| Intermediate | 10 | Conditional Logic | CASE WHEN...THEN, COALESCE, NULLIF, IFNULL |
| Advanced | 11 | Views & Indexes | CREATE VIEW, Clustered vs Non-clustered Indexes, Performance Basics |
| Advanced | 12 | Stored Procedures & UDFs | Stored Procedures, User-defined Functions (Scalar & Table-valued) |
| Advanced | 13 | Transactions | BEGIN, COMMIT, ROLLBACK, SAVEPOINT, ACID Properties |
| Advanced | 14 | Window Functions | ROW_NUMBER, RANK, DENSE_RANK, LEAD, LAG, PARTITION BY |
| Advanced | 15 | CTE (Common Table Exp) | WITH clause, Recursive CTE (Hierarchical Data) |
| Advanced | 16 | Advanced Features | PIVOT / UNPIVOT, Dynamic SQL, JSON handling in SQL |
| Optimization | 17 | Performance Tuning | EXPLAIN ANALYZE, Query Optimization, Covering Index, Joins vs Subqueries |
| Design | 18 | Database Design | Normalization (1NF to BCNF), ER Diagrams, Candidate Keys |
| Bonus | 19 | Modern SQL (2026) | SQL in Big Data (Spark SQL), Percentiles, Running Totals, Cohort Analysis |
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