Today I started with SQL joins, which let you pull data from multiple tables in a single query. So far, I’ve covered:
- INNER JOIN – only matching rows from both tables.
- LEFT JOIN – all rows from the left table, matched where possible.
- RIGHT JOIN – the opposite of LEFT JOIN.
- FULL JOIN – every row from both tables, with matches where possible.
💡 Practical Example Idea: In a clinical setting, you could join a patient demographics table with a lab results table to see both in one view, could be useful for reviewing patient outcomes alongside risk factors.
It’s still conceptual for me, but I can see how joins will be critical for clinical data analysis projects.