🎓 SQL Developer & Database Designer Academy

Welcome to the ultimate SQL Mastery Repository. This workspace is designed to take you from a database beginner to a placement-ready database developer and architect.

All concepts include clear SQL query examples, English explanations, and Marathi (मराठी) translations to make learning highly intuitive.

---

🗺️ SQL Mastery Curriculum

The repository is structured into 10 progressive levels:

1. Level 1: SQL Fundamentals ⭐⭐⭐⭐⭐
   • DBMS definition, CREATE, INSERT, SELECT, filters (WHERE), ordering (ORDER BY), limiters (LIMIT/TOP), updates (UPDATE), deletions (DELETE), alters (ALTER), and drops (DROP).
2. Level 2: Intermediate SQL ⭐⭐⭐⭐⭐
   • Comparisons, logical filters (AND/OR/NOT), LIKE wildcards, IN/BETWEEN ranges, NULL handling (COALESCE/IS NULL), aggregations (SUM/AVG/COUNT), and group partitions (GROUP BY/HAVING).
3. Level 3: Joins Mastery ⭐⭐⭐⭐⭐
   • INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN, SELF JOIN, CROSS JOIN, and joining multiple tables.
4. Level 4: Advanced SQL ⭐⭐⭐⭐⭐
   • Subqueries, correlated subqueries, Common Table Expressions (CTEs), recursive CTE organizational charts, database Views, Temporary Tables, and set operators (UNION/INTERSECT/EXCEPT).
5. Level 5: Window Functions ⭐⭐⭐⭐⭐
   • Analytical row indexings (ROW_NUMBER), ranking bounds (RANK/DENSE_RANK), distributions (NTILE), time-series offsets (LAG/LEAD), values trackers (FIRST_VALUE/LAST_VALUE), and running aggregates.
6. Level 6: Database Design ⭐⭐⭐⭐
   • Keys (Primary, Foreign, Unique, Composite), Constraints, Normal forms (1NF, 2NF, 3NF, BCNF), and Data Warehouse Schemas (Star Schema & Snowflake Schema).
7. Level 7: Programming SQL ⭐⭐⭐⭐
   • Stored Procedures, User-Defined Functions (UDFs), database Triggers, iteration Cursors, and exception handling blocks.
8. Level 8: Performance Tuning ⭐⭐⭐⭐⭐
   • Index types (Clustered, Non-Clustered, Composite), Query Execution Plans (EXPLAIN), range Partitioning, and tuning query write/read bottlenecks.
9. Level 9: Transactions & Security ⭐⭐⭐⭐
   • Transaction boundaries (COMMIT/ROLLBACK/SAVEPOINT), ACID properties verification, shared/exclusive lock states, and privilege controls (GRANT/REVOKE).
10. Level 10: SQL Analytics ⭐⭐⭐⭐⭐
    • CASE conditional groupings, Pivot/Unpivot matrices, time-series intervals, MoM revenue growths, and customer cohort retention analytics.

---

📂 Repository Folder Structure

SQL/
├── index.html                           # Smart Study Web App Entry Point
├── styles.css                           # Web App Stylesheet
├── app.js                               # Web App Script & Live Query Engine
│
├── markdown_notes/                      # Bilingual Study Notes
│   ├── Level_01_Fundamentals.md
│   └── ... (Levels 1-10)
│
├── interview_and_placement/             # Placement Q&As & Coding Problems
│   ├── Level_01_Fundamentals_Prep.md
│   └── ... (Levels 1-10 Prep)
│
└── archive/                             # Preserved original files
    └── 14_SQL/

---

⚡ Smart Study Web Interface

The Smart Study Web App is built locally directly in this workspace. It requires no installation, dependencies, or server setup.

How to open and study:

1. Open the repository folder C:\Users\kadam\.gemini\antigravity\scratch\SQL on your computer.
2. Double-click the index.html file. It will instantly open in your default web browser (Chrome, Edge, Firefox, or Safari).
3. Features inside:
   • Bilingual Notes: Click the "English / मराठी" button in the header to cycle between English explanations, Marathi translations, or seeing both side-by-side.
   • Live SQL Playground: Select a table (employees, departments, sales) from the selector to preview it. Type SQL queries directly in the code editor and click Run Query to see the compiled output tables directly in your browser!
   • Interview Prep Tabs: Switch from "Topics" to "Interview Prep" in the study panel to test yourself with mock interview questions and click-to-reveal answers.