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📘 SQL Mastery • Zero to Interview

SQL Mastery

Learn SQL from Zero to Data Engineer Interview Level — visual lessons, real tables (employees, departments, jobs), and interview patterns.

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Your SQL Learning Path

Follow the 15-phase progression from foundations to interview mastery

🟢 01

Database Fundamentals

What is SQL, Database, Tables, SQL vs NoSQL, Keys, Constraints

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🔍 02

SQL Basics

SELECT, WHERE, DISTINCT, ORDER BY, LIMIT, LIKE, IN, BETWEEN, NULL

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✏️ 03

CRUD Operations

INSERT, UPDATE (with WHERE!), DELETE

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🧮 04

Functions & Aggregation

COUNT, SUM, AVG, MIN/MAX, GROUP BY, HAVING, WHERE vs HAVING

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🔗 05

JOINs

INNER, LEFT, RIGHT, FULL OUTER, SELF, CROSS, Multi-table

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🧩 06

Subqueries & CTEs

Subqueries, Second Highest Salary, CTE (WITH)

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🪟 07

Window Functions

ROW_NUMBER, RANK, DENSE_RANK, PARTITION BY, LAG/LEAD, Running Total

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⚡ 08

Advanced SQL

Execution Order, CASE, Views, Materialized Views, Procedures

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🚀 09

Performance

Indexes, EXPLAIN, Partitioning, Sharding

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🏗️ 10

Data Modeling

Conceptual/Logical/Physical, Normalization 1NF-3NF, OLTP/OLAP, Star/Snowflake

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📝 11

SQL Practice Exercises

40 hands-on exercises — Basic (1-8), Intermediate (9-20), Advanced (21-40) with solutions

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🎯 12

Interview Mastery

Beginner/Intermediate/Advanced Q&A, Framework, Decision Tree, Cheat Sheet

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