Real-world SQL investigations for Product Support and Application Support scenarios.
A hands-on SQL project that simulates real-world investigations performed by Product Support and Application Support Engineers in a SaaS environment.
Rather than solving generic SQL exercises, this project demonstrates how SQL can be used to troubleshoot customer issues, investigate billing problems, analyze subscription status, and review customer support history.
The goal of this project is to simulate the daily responsibilities of a Product Support Engineer by using SQL to investigate customer-reported issues.
This project focuses on:
- Investigating duplicate payments
- Identifying failed transactions
- Monitoring inactive subscriptions
- Reviewing customer ticket history
- Performing root cause analysis using SQL
- PostgreSQL
- DBeaver
- SQL
- Git & GitHub
- Markdown Documentation
The project contains four business tables commonly found in SaaS products.
| Table | Purpose |
|---|---|
| customers | Stores customer information |
| subscriptions | Stores subscription plans and renewal status |
| payments | Stores customer payment transactions |
| support_tickets | Stores customer support requests |
A customer reported being charged twice for a subscription.
Identify duplicate payment transactions.
- GROUP BY
- HAVING
- COUNT()
Customers reported unsuccessful payment attempts.
Retrieve all failed payment transactions.
- WHERE
- Filtering
- Data Investigation
The Customer Success team requested customers whose subscriptions are inactive.
Retrieve inactive subscriptions for follow-up.
- INNER JOIN
- Filtering
- Business Reporting
Before assisting a returning customer, the support engineer needs to review previous support interactions.
Retrieve the customer's complete support history.
- JOIN
- Customer Investigation
- Support Analysis
product-support-sql-lab/
database/
│── schema.sql
│── sample-data.sql
queries/
│── duplicate-payment-investigation.sql
│── failed-payment-investigation.sql
│── inactive-subscriptions.sql
│── customer-ticket-history.sql
scenarios/
│── duplicate-payment.md
│── failed-payment.md
│── inactive-subscription.md
│── customer-ticket-history.md
screenshots/
README.md
- SQL Query Writing
- PostgreSQL
- Database Investigation
- Customer Support Analysis
- Product Support Workflows
- Root Cause Analysis
- Data Troubleshooting
- Technical Documentation
This project demonstrates how SQL supports real Product Support workflows rather than focusing only on academic SQL exercises.
The investigations mirror real customer issues that support engineers encounter in SaaS products.
Omoyele Olaide Elizabeth
Aspiring Product Support Specialist | Application Support | Data Analytics
GitHub: https://github.com/olaide6