CREATE TABLE id_mapping AS SELECT anonymous_id, user_id, MIN(first_seen_at) AS first_seen FROM events WHERE user_id IS NOT NULL GROUP BY anonymous_id, user_id;

Stitching data refers to the process of combining or joining multiple datasets from different sources into a single, unified dataset. The goal is to create a complete view by linking records that belong to the same entity (e.g., customer, product, transaction) across systems.

SELECT * FROM table_a a LEFT JOIN table_b b ON a.email = b.email OR a.phone = b.phone ⚠️ Be careful with OR – it can cause record multiplication. For complex cases (anonymous + logged-in users), build a mapping table.

Yes, life can be mysterious and confusing--but there's much of life that's actually rather dependable and reliable. Some principles apply to life in so many different contexts that they can truly be called universal--and learning what they are and how to approach them and use them can teach us some of the most important lessons that we've ever learned.
My doctorate is in Teaching and Learning. I use it a lot when I teach at school, but I also do my best to apply what I've learned to the life I'm living, and to observe how others live their lives. What makes them happy or unhappy, stressed or peaceful, selfish or generous, compassionate or arrogant? In this book, I've done my best to pass on to you what I've learned from people in my life, writers whose works I've read, and stories that I've heard. Perhaps these principles can be a positive part of your life, too!
Universal Principles of Living Life Fully. Awareness of these principles can explain a lot and take much of the frustration out of the lives we lead.

Stitch Data ~repack~ -

CREATE TABLE id_mapping AS SELECT anonymous_id, user_id, MIN(first_seen_at) AS first_seen FROM events WHERE user_id IS NOT NULL GROUP BY anonymous_id, user_id;