· intermediate
Exploratory Analysis in SQL
You have been handed a database and no documentation. Learn the queries that tell you what is in it, what is wrong with it, and what it is trying to say.
Written in house, from the work rather than from a syllabus. Every example is one we would use ourselves, and every exercise is checked against the same engine that grades your answer.
What you’ll learn
- Profile an unfamiliar table before drawing conclusions from it
- Quantify NULLs, duplicates and impossible values
- Handle dates, gaps and time ranges without off by one errors
- Describe a distribution rather than reporting only an average
- Pivot rows into columns for a readable summary
- Build a retention cohort from raw event rows
Before you start
- · Data Manipulation in SQL, or comfort with CTEs and window functions
- · Familiarity with joins and GROUP BY