Data Analytics Handbook

A structured, clean, and beginner-friendly collection of notes as I learn SQL, Excel, Power BI, Python, and Data Analytics — one concept every day.

About This Repository

This repo documents my daily learning journey into the world of Data Analytics. Everything here is handwritten, example-driven, and focused on helping me (and you!) build a strong foundation for real-world data work:

• SQL from scratch → advanced
• Data cleaning, transformations
• Excel & Google Sheets
• Visualizations (Power BI / Tableau)
• Python for analytics
• Case studies & mini projects

These notes are designed to be:

• Easy to revise
• Practical
• Hands-on
• Real-world focused

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Current Learning Roadmap

1️⃣ Basics & Data Retrieval — (Completed)

• SELECT, FROM, WHERE
• ORDER BY, LIMIT
• BETWEEN, LIKE, IN, NOT

2️⃣ Joins & Relationships — (In Progress)

• INNER, LEFT, RIGHT, FULL, CROSS

3️⃣ Aggregation & Grouping — (Next)

• GROUP BY, HAVING
• COUNT, SUM, AVG, MAX, MIN

4️⃣ Subqueries & CTEs — (Upcoming)

• Nested queries
• WITH statements

5️⃣ Data Cleaning in SQL

• CASE WHEN
• Handling NULL
• COALESCE
• Text functions

6️⃣ Window Functions

• ROW_NUMBER, RANK
• Running totals
• Moving averages

7️⃣ Analytical Thinking with SQL

• Answering business questions
• Real-world datasets
• Creating insights

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Progress Bar

SQL Progress:

• Basics: 100%
• Joins: 70%
• Aggregations: 0%
• Subqueries/CTEs: 0%
• Data Cleaning: 0%
• Window Functions: 0%
• Analytical Thinking: 0%

Folder Structure

data-analytics-notes/
 ├── SQL/
 │    ├── 01_basics.md
 │    ├── 02_joins.md
 │    ├── 03_group_by.md
 │    ├── 04_subqueries_ctes.md
 │    ├── 05_data_cleaning.md
 │    └── 06_window_functions.md
 ├── Excel/
 ├── PowerBI/
 ├── Python/
 └── README.md

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Learning Principles

• One topic a day — no burnout
• Write small notes, not essays
• Practice with examples
• Share progress publicly
• Revisit hard concepts weekly

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Follow My Journey

Twitter (Data Analytics updates): [Add your new DA account here]

Main account (Indie hacking): [Your main Twitter link]

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Support

If these notes help you, feel free to star the repo. It keeps me motivated to keep learning and sharing.