SQL at Work

A SQL analysis of Yelp business data using PostgreSQL, exploring review distribution across business categories with string-splitting techniques.

Using DENSE_RANK() and GROUP BY to rank Airbnb guests by total messages sent, and why window functions let us skip the CTE entirely.

StrataScratch practice solution. Using LAG(), PARTITION BY, and a CTE to find users with consecutive purchases within 7 days transactions.

Learn how to identify projects where prorated employee costs exceed budget using joins, aggregations, and the HAVING clause.