Built by an Ex-Google Growth Data Scientist

SQL practice platform forBusiness Analytics domains

AI analysts and tutors that evaluate your queries, explain your logic, and teach you what your SQL actually does. Built for data and technical professionals who write SQL or use AI to generate it — but struggle to explain it. Practice SQL on real business datasets across Growth, SaaS, Marketing, Product, and Finance.

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100

SQL Challenges

Analytics Domains

AI Tools

Difficulty Levels

queryflo.ai/challenges/42

Dashboard

Challenges

Text to SQL

Data Sandbox

Learn

Growth Analytics

Progress

GrowthIntermediateCohort Retention at Month 3

3 / 20

Your Task

Using the cohort_retention table, find the month-3 retention rate for each cohort.

SQL Editor

⌘+Enter to run

SELECT cohort_month,

period_number,

ROUND(retained::numeric / users * 100, 1) AS retention_rate

FROM growth.cohort_retention

WHERE period_number = 3

ORDER BY cohort_month

Correct · 8 rows+20 XP

cohort_month	period_number	retention_rate
2024-01-01	3	34.2
2024-02-01	3	31.8
2024-03-01	3	36.5

AI Feedback

Type casting to ::numeric forces decimal division — without it, Postgres does integer math and the percentages collapse to 0 or 1.

Code Review

✅ Good: schema-prefixed, no SELECT *, type-safe division. ⚠️ Add WHERE users > 0 — empty cohorts would divide by zero.

Insight

March 2024 cohort retains at 36.5%, the highest in the result set. February drops to 31.8% — a 4.7-point gap between adjacent cohorts. What changed in February's acquisition mix?

The Problem

Anyone can write SQL now. Few can explain it.

In code reviews and technical interviews, you're tested on both: writing a production-grade query AND explaining the logic — without AI.

You write SQL — or AI writes SQL for you — but you can't explain your query when it matters

Generic SQL tutorials use toy datasets with no real business domains

No feedback on whether your query is production-ready or just "correct"

SQL technical interviewers grade how you explain your logic — not just whether the query runs

The Solution

Practice SQL on real business data. Learn to explain every query.

Every challenge is built around a real business scenario. Queryflo evaluates your query, explains your logic, and teaches you what your query actually does — so you can explain your reasoning when it matters.

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Domain-specific schemas

Growth, SaaS, Marketing, Product, Finance — real business verticals

8 AI tools per challenge

Explanation, Code Review, Exec Summary, Schema Chat — all streaming

Instant validated feedback

Your output columns are checked against expected results automatically

XP + streak system

Gamified progress tracking across 100 challenges and 3 difficulty levels

AI Analysts & Tutors

Explains and teaches you what your query is actually doing — in bite-sized lessons

Responsible AI governance

Every AI feature is transparent, explainable, and aligned with your learning

5 Business Analytics Domains

Real schemas. Real business problems.

Challenges span 5 domains, each modelled on how real companies store their data. Every schema covers Beginner, Intermediate, and FAANG-level Advanced difficulty.

Growth

SaaS

Marketing

Product

Finance

5 more domains shipping after launch — Healthcare, HR, Operations, E-commerce, Sales.

Beginner

SELECT, WHERE, GROUP BY, JOINs, aggregations

Intermediate

CTEs, subqueries, date functions, complex joins

Advanced

Window functions, cohort analysis, LTV:CAC, Rule of 40

How It Works

From question to production-ready SQL in 4 steps

Pick a challenge

Choose from 100 challenges across 5 domains and 3 difficulty levels. Filter by domain or difficulty.

Write your SQL

VS Code-quality Monaco editor with SQL syntax highlighting. Use the schema panel to understand the data model.

Get validated

Your result columns are checked automatically. The system knows if you're right — no manual comparison needed.

Learn from AI

8 AI tools analyze your query: explain it, review governance, summarize the insights, and answer schema questions.

AI-native SQL practice platform.

Not one AI tool. Eight.

Built with responsible AI governance. Every AI feature is transparent, explainable, and designed to build your understanding — not replace it.

AI Code Reviewer

Auto-runs after every correct query. Checks for SELECT *, missing LIMITs, implicit joins, NULL handling gaps, and non-SARGable predicates.

AI Answer Explanation

Evaluates your logic for the correct approach, explains your query, and teaches you what the query does in bite-sized lessons.

Exec Summary & Insight

Turns your query results into a CEO-level narrative — key findings, trend identification, and a business recommendation. The skill interviewers actually test.

Schema Explorer (Ask the DB)

Chat with an AI that knows your challenge's schema. Ask 'How do I join these tables?' or 'Which column stores churn date?' and get schema-aware answers.

Text to SQL + AI Judge

Paste a schema, ask in plain English, get SQL. Then run the 8-step AI Judge for Accuracy, Efficiency, and Readability scores out of 10.

Synthetic Data Generator

Describe any business scenario. Get a full practice dataset with CREATE TABLE, INSERT statements, and example queries — generated instantly.

Everything You Need

One platform. Complete SQL mastery.

100 Real-World SQL Challenges

Authentic business schemas — growth analytics, SaaS metrics, marketing funnels, product events, and FP&A finance. The same data models used at FAANG companies.

AI-Powered Feedback Engine

Four AI assistants built into every challenge: Answer Explanation, Code Reviewer (SQL governance), Exec Summary (data storytelling), and Schema Explorer (Ask the DB).

Text to SQL + AI Judge

Paste your schema, ask in plain English, get production-ready SQL — then run the 8-step AI Judge review: Accuracy, Efficiency, and Readability scored out of 10.

Synthetic Data Sandbox

Describe any business scenario and generate a complete practice dataset — CREATE TABLE, INSERTs, and 3 example queries — ready to run immediately.

SQL Guides Library

44 topics categorized as Beginner, Intermediate, and Advanced — from SQL SELECT to Window Functions — all linked to the challenges that use them.

Growth Analytics Library

Deep-dive reference frameworks: HEART (UX quality), AARRR (user lifecycle), Marketing Acquisition, and Experimentation & A/B Testing.

What Analysts Say

Built for business analytics

"Finally, SQL practice that feels like real work. The cohort analysis challenges are exactly what I got asked at my Meta loop."

Data Analyst, Meta

"The AI Code Reviewer caught three governance issues in my query I wouldn't have noticed. This is how SQL should be taught."

Growth Analyst, Stripe

"HEART framework + AARRR in the same platform as SQL challenges? This is the only prep tool I needed for my Google PM data round."

Product Manager, Google

Pricing

Simple, transparent pricing

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5 SQL challenges
Daily SQL Task
Learn SQL for Business
Limited business domains
Interactive SQL editor
Growth Analytics Guide
Limited shareable badges
Progress & streak tracking
10 AI credits (Text-to-SQL, Explain, Exec Summary, AI Judge, Ask the DB, Data Sandbox)
All 100+ SQL challenges
All business analytics domains
Unlimited AI access
Mock interview
Advanced AI tools

Ready to level up your SQL?

100 challenges. 8 AI tools. Real business analytics.

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