annotation example

src/books/migrations/0002_alter_book_author.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.0.6 on 2024-06-05 11:17
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('books', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='book',
+            name='author',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='books', to='books.author'),
+        ),
+    ]

src/books/models.py

@@ -1,11 +1,13 @@
 from app.models import TimestampedModel
 from django.db import models
+from django.db.models.manager import Manager
 
 
 class Author(TimestampedModel):
     name = models.CharField(max_length=255)
+    books: "Manager[Book]"
 
 
 class Book(TimestampedModel):
-    author = models.ForeignKey(Author, on_delete=models.CASCADE)
+    author = models.ForeignKey(Author, on_delete=models.CASCADE, related_name="books")
     name = models.CharField(max_length=255)