order_by ('-created_at') ← What is "ー"? ?? ?? [Beginner learns python with a reference book]

Introduction

Using Takashi Otaka, "Learning by Moving! Introduction to Python Django Development" I'm a beginner who started learning python and Django.

I've been studying programming for about 4 months using ruby / rails, When I changed jobs as an engineer, I decided to use python, so I started studying with this book in my hand.

Since I am a de-class amateur, I would be very grateful if you could comment on supplements and suggestions.

Overview

[Reference book applicable part] Chapter11 08 Add Pagination to Diary List Page (Kindle Position No.3995) List 11.11

[Clogged point]

order_by('-created_at')

What does'-created_at' mean? ??

result

It seems to represent ascending order and descending order. Surprising for ASC and DISC.

↓ Ascending order (old date → new date)

order_by('created_at')

↓ Descending order (new date → old date)

order_by('-created_at')

References

Takashi Otaka, "Learn by Moving! Introduction to Python Django Development"

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