Add MergedBookDataModel

bookwyrm/migrations/0197_mergedauthor_mergedbook.py

@@ -0,0 +1,48 @@
+# Generated by Django 3.2.24 on 2024-02-28 21:30
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bookwyrm", "0196_merge_pr3134_into_main"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="MergedBook",
+            fields=[
+                ("deleted_id", models.IntegerField(primary_key=True, serialize=False)),
+                (
+                    "merged_into",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="absorbed",
+                        to="bookwyrm.book",
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+        migrations.CreateModel(
+            name="MergedAuthor",
+            fields=[
+                ("deleted_id", models.IntegerField(primary_key=True, serialize=False)),
+                (
+                    "merged_into",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="absorbed",
+                        to="bookwyrm.author",
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+    ]

bookwyrm/models/book.py

@@ -1,4 +1,5 @@
 """ database schema for books and shelves """
+
 from itertools import chain
 import re
 from typing import Any
@@ -192,9 +193,13 @@ class Book(BookDataModel):
         """properties of this edition, as a string"""
         items = [
             self.physical_format if hasattr(self, "physical_format") else None,
-            f"{self.languages[0]} language"
+            (
-            if self.languages and self.languages[0] and self.languages[0] != "English"
+                f"{self.languages[0]} language"
-            else None,
+                if self.languages
+                and self.languages[0]
+                and self.languages[0] != "English"
+                else None
+            ),
             str(self.published_date.year) if self.published_date else None,
             ", ".join(self.publishers) if hasattr(self, "publishers") else None,
         ]
@@ -451,6 +456,34 @@ class Edition(Book):
         return queryset
 
 
+class MergedBookDataModel(models.Model):
+    """a BookDataModel instance that has been merged into another instance. kept
+    to be able to redirect old URLs"""
+
+    deleted_id = models.IntegerField(primary_key=True)
+
+    class Meta:
+        """abstract just like BookDataModel"""
+
+        abstract = True
+
+
+class MergedAuthor(MergedBookDataModel):
+    """an Author that has been merged into another one"""
+
+    merged_into = models.ForeignKey(
+        "Author", on_delete=models.PROTECT, related_name="absorbed"
+    )
+
+
+class MergedBook(MergedBookDataModel):
+    """an Book that has been merged into another one"""
+
+    merged_into = models.ForeignKey(
+        "Book", on_delete=models.PROTECT, related_name="absorbed"
+    )
+
+
 def isbn_10_to_13(isbn_10):
     """convert an isbn 10 into an isbn 13"""
     isbn_10 = re.sub(r"[^0-9X]", "", isbn_10)