Roadmap
Day 20 · Relationships 55 min 40 XP
🔗JOINs: combine tables
Data lives in separate tables so nothing is stored twice. A JOIN stitches them back together using a shared column, which is how you turn customer_id 3 into the name Chloe.
What you'll learn
- Join two tables on a key
- Choose between INNER and LEFT JOIN
- Find rows with no match
A peek inside
Keys connect tables
The rest of Day 20 is a Pro lesson
You're on the free Explorer plan — you get the intro and the video. Go Pro to open the full guided lesson (and all 30 days).
- 3 deep-dive lessons
- A copy-paste worked example
- 3 hands-on practice tasks
- Studio task: Stitch the tables together
- 3-question quiz, up to 45 XP
- 4 quick-glance glossary cards
- 40 XP + streak tracking
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