20 minutes
A short screen: three questions, easier ones first.
3 questions
Interview mode
Practice a SQL interview on the clock.
Each question uses the same editor, schema, sample rows, hints, and result check as the exercise bench. A correct result counts only if you have not revealed the reference solution.
Mock interview
Five questions in increasing difficulty, with a 45-minute timer. You get a score and a review of every question at the end.
Timed practice sets
45 minutes
A standard loop: five questions across the bank.
5 questions
60 minutes
A long loop: seven questions, ending on the harder ones.
7 questions
Question categories
Joins
Connect related tables and find rows that do not match.
4 questions in the bank
Aggregation
Summarize a business metric and keep only the groups that matter.
4 questions in the bank
Subqueries
Compare a row with a benchmark computed in a separate query.
4 questions in the bank
Window functions
Rank, number, or accumulate rows without collapsing them.
4 questions in the bank
Data cleaning
Normalize messy text, blanks, and duplicate identities.
4 questions in the bank
Date analysis
Bucket, age, and compare dates with SQLite date functions.
4 questions in the bank
Case studies
Answer a multi-step business question with more than one idea.
4 questions in the bank
Performance
Finish a set or a mock interview and the score breakdown will stay on this device.