PostgreSQL / SQLite / DuckDB

SQL Case Studies

15+ real-world SQL patterns with clean documentation and reproducible examples

15 Case Studies

5 Categories

3 Databases

Skills Demonstrated

☍

Window Functions

ROW_NUMBER, RANK, LAG/LEAD, Moving Averages

↺

CTEs & Recursion

Multi-step pipelines, hierarchy traversal

📈

Analytics Metrics

Retention, churn, MRR, ARR, LTV

⚡

Query Optimization

Index-aware patterns, anti-pattern avoidance

Case Studies

Quick Start

bash

# Clone the repository
git clone https://github.com/TADSTech/SQL-STUDIES.git
cd SQL-STUDIES

# Load sample data into DuckDB
duckdb case_studies.duckdb < data/sample_schema.sql

# Run any case study query
duckdb case_studies.duckdb