README.md

SQL for Data Engineering

This repository is focused on SQL practice for Data Engineering using LeetCode problems.

Why this repo

The goal is to build strong SQL skills used in data engineering work:

• writing clean analytical queries
• handling joins, aggregations, and window functions
• improving query readability and correctness
• practicing interview-style SQL problems

Project Structure

src/leetcode_problems/
├── easy/
│   ├── joins/
│   └── date_functions/
├── medium/
│   ├── aggregation/
│   └── sequences/
└── hard/
    ├── sequences/
    └── window_functions/

File Naming Convention

For each problem:

• SQL solution: <id>_<slug>.sql
• Optional notes: <id>_<slug>.md

Example:

• src/leetcode_problems/easy/joins/0175_combine_two_tables.sql
• src/leetcode_problems/easy/joins/0175_combine_two_tables.md

How to use

1. Pick one SQL problem.
2. Place it in the correct difficulty/topic folder.
3. Add notes for approach and edge cases if needed.
4. Keep one problem per file pair.

Long-term goal

Create a clean, searchable SQL problem bank for data engineering interview prep and daily SQL practice.