Hello Reader, Here's a fact of analyst life: most of the people who use your analysis will never use SQL. Instead, they'll use spreadsheets and reports. Your director doesn't open pgAdmin. Your marketing team doesn't "connect to the database". They open the Excel file or Google Sheet you sent them. And if the data you exported requires 20 minutes of cleanup before it's usable (reformatting dates, splitting columns, fixing number formats) you've done extra work that didn't need to happen....
7 days ago • 6 min read
Hello Reader, Most analysts panic when they get a note like this on a random Tuesday afternoon (from the CEO): "Revenue feels off this quarter. Can you figure out what's happening before the board call at 4:30?" Great. You have 90 minutes. No time to build a comprehensive analysis. No time to make it pretty. You need to diagnose the problem (super fast) and deliver a clear answer. Lucky you. You're going to learn the way a seasoned pro handles this situation. I call it The Gordon Ramsay...
14 days ago • 5 min read
Hey Reader -- I'm trying something new this week! Can you take a minute to fill out this quick survey? Thanks in advance! Okay, on to this week's topic: A common question I get from readers is some version of: "This Summit Adventures stuff is great, but I work in healthcare (or SaaS, or retail, or finance). How does this apply to me?" The honest answer: every SQL pattern you've learned in this newsletter translates directly to your industry. The table names change. So do column names. The...
21 days ago • 5 min read
Hello Reader, Imagine you're a business analyst at Summit Adventures (the fake adventure tourism company I created to teach real-world business analytics concepts). Your CEO asks a common question: "Who are our best customers?" If you pull a list sorted by total spend, you'll get a spreadsheet with hundreds of rows. Not useful because no one acts on a list of 500 customers. And certainly not the CEO. What they actually need are segments: 3-5 groups with clear labels, clear revenue impact, and...
28 days ago • 5 min read
Hello Reader, Here's a scenario that happens more often than anyone admits: You build a report. Your director uses it in a board presentation. A week later, someone notices the customer count includes 58 records with obviously fake email addresses like evan.clarke743@noemail. The report wasn't wrong. The data underneath it was dirty. And now your credibility takes a hit. Bummer. Not because of your SQL skills, but because you didn't check the final product before sending it off. Data quality...
about 1 month ago • 4 min read
Hey Reader, Last month, we covered LEFT JOIN to find customers who never booked. That's one type of absence — people who never showed up. But there's another kind that's even more expensive: people who showed up, committed, and then left. The dreaded cancellation. Customers who said "yes", then said "actually, never mind". In the Summit Adventures database (the fake adventure tourism company I created to help people learn business analytics), nearly 47% of all bookings end in cancellation....
about 1 month ago • 4 min read
Hello Reader, This week's newsletter is a bit different. There's SQL in here, but the real topic is career strategy. Because one of the most common questions I get from readers is some version of: "I've been learning SQL for a few months. How do I prove I can actually do this job?" The honest answer: a portfolio of 2-3 projects that demonstrate business thinking, not just technical syntax. The problem is most portfolios I've reviewed look the same. A Kaggle competition. A tutorial from...
about 2 months ago • 5 min read
Hello Reader, A common analytics question that sounds simple but isn't: "Which customers have booked the same type of expedition more than once?" You can't answer this with a regular JOIN between two different tables. The information lives in one table. You need to compare rows within that table to find patterns. That's what a self-JOIN does. It joins a table to itself. It sounds unusual, but once you see the pattern, you'll recognize situations where it's exactly what you need. The Business...
about 2 months ago • 4 min read
Hello Reader, You've built a clean customer report. Locations, booking history, revenue by region. You send it off to whoever asked for it. Ten minutes later: "Why does this report show blank cells in the location column? And why do the totals not add up?" Welcome to the NULL problem. You're going to learn how to solve it once and for all today. In the Summit Adventures database (the fake adventure tourism company I created to help people learn business analytics), 78.2% of customers don't...
2 months ago • 4 min read