Free data & SQL lessons for career switchers
Data skills, explained so they finally click.
Every lesson starts with a real-world analogy, then proves it on real data from one practice coffee shop. Start in free Google Sheets with nothing to install, then level up to SQL. No jargon, no assumed knowledge. Just the "ohhh, that's it" moment, every Tuesday.
Nov 3Episodes 1–3 go live Tuesday, November 3, 2026
| CustomerID | FirstName |
|---|---|
| 1 | Maya |
| 2 | Jordan |
| 7 | Olivia |
| OrderID | CustomerID |
|---|---|
| 17 | 1 |
| 20 | 1 |
| 39 | 2 |
| 56 | 1 |
| FirstName | OrderID |
|---|---|
| Maya | 17 |
| Maya | 20 |
| Maya | 56 |
| Jordan | 39 |
| Olivia | NULL |
ohhhOlivia never ordered, but a LEFT JOIN keeps her anyway. Everyone on your list stays, with their orders if they have any.
How every lesson works
Concept first. Then proof.
Most tutorials start with syntax. We start with the idea, so the syntax has somewhere to land.
Something you already know
A guest list, a coffee receipt, a junk drawer. Each concept gets one real-world picture that sticks.
A primary key is the order number on your coffee ticket: no two are ever the same.
Watch the tables move
Animated diagrams show exactly what the database does: rows matching, keys lining up, NULLs appearing.
Customers ⟶ match on CustomerID ⟶ Orders
Do it yourself
Every lesson ends with you running it on the same free data: first in Google Sheets, then in SQL Server. Follow along and break things safely.
=XLOOKUP(…) → LEFT JOIN
Playlist 1 · Data Science Basics · Nov 2026 – Jan 2027
Start in a spreadsheet. Finish with every join.
No SQL Server needed. The Basics playlist teaches every core idea in free Google Sheets, one lesson each Tuesday. Then the SQL playlist does it all again in SQL, faster, because you already get it.
Data 101 B1–B4
- B1What is data?
- B2Dirty data: garbage in, garbage out
- B3What clean data looks like
- B4Why your spreadsheet isn't a database (yet)
Keys & relationships B5–B6
- B5Primary & foreign keys
- B6One-to-one, one-to-many, many-to-many
Joins, no SQL B7–B12
- B7XLOOKUP is a LEFT JOIN
- B8INNER vs LEFT (+ anti-join)
- B9Why rows multiply
- B10FULL OUTER: compare two lists
- B11CROSS & SELF JOIN
- B12UNION vs UNION ALL
Summarize & level up B13–SQL0
- B13Pivot tables = GROUP BY
- B14The full course in one video
- SQL0Install SQL Server (free)
Free download
One coffee shop. Every lesson.
Bean There Coffee Co. is a fictional chain with 5 stores, 20 customers and 60 orders. Every video uses it, so you learn one dataset deeply instead of forty random ones. The starter kit has it in two formats, one folder each.
Start here. Nothing to install.
- BeanThereCoffee_Workbook.xlsx
- Install guide (PDF, 2 pages)
Works in free Google Sheets or Excel 365 on Mac, PC or Chromebook. Made for the Data Science Basics playlist.
When you're ready for SQL.
- BeanThereCoffee_PracticeDB.sql
- Install guide (PDF, 2 pages)
A free SQL Server + SSMS setup on Windows, step by step. One script builds all 9 tables.
About
Taught by someone who does this for a living.
Hi, I'm Will. I run The Data Science Tutor, and I'm a working data professional who got tired of tutorials that start in the middle. If you're switching careers and every job post says "SQL required," this channel is built for you.
You won't need a math degree or any code experience. You'll need about ten minutes a week and a willingness to ask "wait, why?" That's the question every lesson answers.
Clean data, clear mind.