Jamal Hansen

Run a SQL query twice. Get different row orders. That's not a bug.

Databases optimize execution based on indexes, data volume, and memory. Those optimizations can change between queries.

If order matters, you need ORDER BY. And here's where SQL beats Python: mixed sort directions in one line.

ORDER BY signup_date DESC, name ASC

In Python, that requires cmp_to_key or multiple sorting passes. SQL handles it cleanly.

https://jamalhansen.com/blog/order-by-sorting-your-results

#SQL #Python #DuckDB #DataScience #Programming

ORDER BY: Sorting Your Results

SQL returns rows in no guaranteed order. Run the same query twice and you might get different results. ORDER BY gives you control, like Python's sorted() with key functions.

Jamal Hansen
Feb 23 at 3:35pmWeb
Show threadYiorgos  Feb 23
@ham_jansen Of course nobody uses Python to query a db. Or do they?
Show threadJamal HansenFeb 23
@yiorgos Lol, I've seen it once or twice. Maybe even done it myself 😀