The Dataquest Download

Level up your data and AI skills, one newsletter at a time.

Each week, the Dataquest Download brings the latest behind-the-scenes developments at Dataquest directly to your inbox. Discover our top tutorial of the week to boost your data skills, get the scoop on any course changes, and pick up a useful tip to apply in your projects. We also spotlight standout projects from our students and share their personal learning journeys.

Learn How to Summarize Data In SQL

Hey Dataquesters–

It’s Casey again, your friend and director of course development at Dataquest. I hope you’ve been enjoying our 6-week SQL summer challenge so far. If you missed last week’s post, don’t worry – it’s not too late to join in. You can get started here. This week, we’re moving on to Week 2 of the challenge with our Summarizing Data in SQL course.

As I mentioned before, we use SQL every day at Dataquest to keep an eye on how our courses are doing and quickly fix any problems that come up. But with so many learners working through numerous screens, how do we find the important patterns in all that information? That’s where summarizing data in SQL comes in.

SQL lets you quickly calculate statistics and spot trends, even in huge datasets. With tools like SUM(), which adds up values, AVG(), which calculates the average, and COUNT(), which counts the number of rows, you can create helpful summaries of your data. And when you use those tools together with the GROUP BY command, which groups rows based on a specific column, you can look at your data from different angles – like grouping course data by topic to see how engagement compares across subjects.

At Dataquest, we depend a lot on this kind of data summarization in SQL to pull out useful insights from all of the data we gather. One of the most important reports we use looks at how many people complete each course over time. This lets us see which courses have the best engagement and figure out which ones might need some work.

Another key metric for us is how many times learners attempt each screen in a course. By filtering the summarized data, we can pinpoint specific screens that might be confusing or too hard. These insights help us constantly improve our courses and make sure you’re getting the most out of your learning.

I’m always amazed by how much we can learn from summarizing and filtering our data with SQL. It’s not just about finding problems – it’s also about discovering opportunities to make our content even better and give you an awesome experience.

That’s why I’m excited for you to check out the Summarizing Data in SQL course. You’ll get hands-on practice with real datasets, building the skills you need to take on data analysis challenges at work. You’ll practice using aggregate functions, GROUP BY, and filtering to uncover insights from real-world datasets.

As you go through the material, think about how you could apply these ideas to your own projects. What interesting questions could you answer by summarizing and segmenting your data?

The ability to summarize data separates the SQL pros from the beginners. It’s how you go from just pulling data to actually finding meaningful insights that influence decisions.

Stay tuned for more SQL content in next week’s newsletter. Until then, enjoy the learning process and have fun summarizing data in SQL!

Casey

Week 2 SQL Summer Challenge

Week 2 SQL Summer Challengw

In the Summarizing Data in SQL course, you’ll learn how to summarize and aggregate data to draw meaningful insights. This self-paced course consists of 4 lessons and takes only 4 hours to complete. By the end, you’ll have learned:

Aggregate Functions with SQL: Learn to use functions like COUNT, SUM, AVG, MIN, and MAX to summarize data.
Summary Statistics with SQL: Get better at analyzing data by combining aggregate functions with WHERE clauses, scalar functions, and arithmetic operations.
Group Summary Statistics with SQL: Find out how to use the GROUP BY clause to organize and analyze grouped data.
Multiple Group Summary Statistics: Go further by grouping data based on multiple criteria and filtering results to focus on what matters.

At Dataquest, we believe in learning by doing. We strongly encourage you to complete the guided project and share it in the Community. This provides valuable peer feedback, helping you refine your projects to look more advanced and professional.

All the best!

What We're Reading

📖 AI Advancements: A Midyear Review

A summary of the latest AI advancements over the past year, written by Professor Mollick of the University of Pennsylvania. Read more

📖 NVIDIA Warp (GitHub Repo)

NVIDIA Warp is a Python framework for high-performance simulation and graphics, JIT compiling Python functions to efficient CPU or GPU code. Ideal for physics simulation, robotics, and geometry processing, and integrates with PyTorch and JAX. Read more

📖 How to Actually be Data-driven

How can startup founders be truly data-driven? Learn to set up a Weekly Metrics Review meeting to track key driver metrics leading to revenue. This article covers identifying important metrics, ensuring accountability, and using automated dashboards for effective data-driven decisions. Read more

What's new

Give 20% Get $20

Now is the perfect time to share Dataquest with a friend. Gift a 20% discount, and for every friend who subscribes, earn a $20 bonus. Use your bonuses for digital gift cards, prepaid cards, or donate to charity. Your choice! Click here

Community highlights

Sharing your projects and reviewing projects from other learners are among the best practices to enhance your skills. Every week we will share a project from the community. The top pick wins a $20 gift card!

This week, we feature Cyprian‘s project on Investigating Fandango Movie Ratings. Cyprian’s analysis provides a clear and concise look into movie rating discrepancies, supported by well-crafted figures that enhance his findings. His work is a great example of effective data analysis and storytelling.

Want your project in the spotlight? Share it in the community.

Learner Tip of the Week

Q: What are the top three lessons you learned from working on projects?

1. Even though I could find answers similar to my questions online, I often still need to experiment with the code until I solve it.

2. When I write complicated code, it’s good to comment on it clearly and neatly. It helps me a lot when I revisit my lines of code after a short break.

3. Very often, people only skim through your project quickly. To attract people to read the details of my project, I have learned to keep the introduction (introduction, goals, and key results) concise and interesting and the plots pretty and simple.

Shi Pey Wong

Data Scientist

High-fives from Vik, Celeste, Casey, Anna P, Anna S, Anishta, Bruno, Elena, Mike, Daniel, and Brayan.

2025-07-09

Use SQL or Python? With PySpark, You Don’t Have to Choose

Learn to analyze census trends with PySpark, uncover traffic patterns using Python, and explore efficient SQL workflows for large datasets. Read More
2025-07-02

Learn to Set Up PostgreSQL with Docker (No Installation Needed)

Set up PostgreSQL with Docker, analyze I-94 traffic, predict heart disease, improve Python plots, and explore large-scale data with RDDs. Read More
2025-06-25

Struggling with Slow Python Scripts and Crashing Excel files?

Explore PySpark locally, build your first Spark app, master ETL pipelines with Airflow on AWS, and learn from impressive community projects. Read More

Learn faster and retain more.
Dataquest is the best way to learn