Public viewer
The journey of every round
Every round-trip in the corpus is public. Open one to see the prompt, the zero-point index, the baseline response, the enhanced response, and how each grader read the difference. Leave a comment if a grader's reading lands — or doesn't.
Use HAVING to filter aggregate results: orders with more than 5 line items.
Write a SQL query joining 4 tables (customers, orders, line_items, products) to produce a customer-order-product report.
Find products in the top 10 percent by revenue using NTILE.
Use EXISTS to find customers with at least one cancelled order.
Write a recursive CTE to walk an employee-manager hierarchy from any starting employee.
Use UNION to combine current_employees and former_employees, marking source.
Calculate a moving 7-day average of daily_sales using a window function.
Find customers who placed orders in consecutive calendar months.
Pivot a table of monthly_sales (month, year, total) to columns per month.
Use ROW_NUMBER to deduplicate orders, keeping the most recent per customer.
Find duplicate rows in an emails table based on email address.
Write a self-join to find pairs of employees with the same manager.
Calculate the percentage of total sales each product represents.
Use a CTE to find the longest chain of referrals in a referrals table.
Write a SQL query that returns customers with more than 3 orders.
Find the second-highest salary in an employees table.
Calculate the running total of sales by date using a window function.
Use a window function to rank orders within each customer.
Find products that have never been ordered using a left join.
What is the least common multiple of 4, 6, and 9?
Convert 5 over 8 to a percentage.
What is the area of a circle with radius 5? Use pi approximately 3.14159.
Simplify the expression 3x squared times 4x cubed.
If x plus y equals 10 and x minus y equals 4, what are x and y?