Fixed #25128 -- Fixed SQLite SchemaEditor crash when adding a ForeignObject field.

django/db/backends/sqlite3/schema.py

@@ -77,10 +77,10 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
           4. delete the "app_model__old" table
         """
         # Work out the new fields dict / mapping
-        body = {f.name: f for f in model._meta.local_fields}
+        body = {f.name: f for f in model._meta.local_concrete_fields}
         # Since mapping might mix column names and default values,
         # its values must be already quoted.
-        mapping = {f.column: self.quote_name(f.column) for f in model._meta.local_fields}
+        mapping = {f.column: self.quote_name(f.column) for f in model._meta.local_concrete_fields}
         # This maps field names (not columns) for things like unique_together
         rename_mapping = {}
         # If any of the new or altered fields is introducing a new PK,
@@ -98,7 +98,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         for field in create_fields:
             body[field.name] = field
             # Choose a default and insert it into the copy map
-            if not field.many_to_many:
+            if not field.many_to_many and field.concrete:
                 mapping[field.column] = self.quote_value(
                     self.effective_default(field)
                 )

tests/schema/models.py

@@ -89,6 +89,14 @@ class BookWithoutAuthor(models.Model):
         db_table = "schema_book"
 
 
+class BookForeignObj(models.Model):
+    title = models.CharField(max_length=100, db_index=True)
+    author_id = models.IntegerField()
+
+    class Meta:
+        apps = new_apps
+
+
 class IntegerPK(models.Model):
     i = models.IntegerField(primary_key=True)
     j = models.IntegerField(unique=True)

tests/schema/tests.py

@@ -13,7 +13,7 @@ from django.db.models.fields import (
     TextField, TimeField,
 )
 from django.db.models.fields.related import (
-    ForeignKey, ManyToManyField, OneToOneField,
+    ForeignKey, ForeignObject, ManyToManyField, OneToOneField,
 )
 from django.db.transaction import atomic
 from django.test import TransactionTestCase, skipIfDBFeature
@@ -22,10 +22,10 @@ from .fields import (
     CustomManyToManyField, InheritedManyToManyField, MediumBlobField,
 )
 from .models import (
-    Author, AuthorWithDefaultHeight, AuthorWithEvenLongerName, Book, BookWeak,
-    BookWithLongName, BookWithO2O, BookWithoutAuthor, BookWithSlug, IntegerPK,
-    Note, NoteRename, Tag, TagIndexed, TagM2MTest, TagUniqueRename, Thing,
-    UniqueTest, new_apps,
+    Author, AuthorWithDefaultHeight, AuthorWithEvenLongerName, Book,
+    BookForeignObj, BookWeak, BookWithLongName, BookWithO2O, BookWithoutAuthor,
+    BookWithSlug, IntegerPK, Note, NoteRename, Tag, TagIndexed, TagM2MTest,
+    TagUniqueRename, Thing, UniqueTest, new_apps,
 )
 
 
@@ -1507,6 +1507,15 @@ class SchemaTests(TransactionTestCase):
         with connection.schema_editor() as editor:
             editor.add_field(BookWithLongName, new_field)
 
+    def test_add_foreign_object(self):
+        with connection.schema_editor() as editor:
+            editor.create_model(BookForeignObj)
+
+        new_field = ForeignObject(Author, from_fields=['author_id'], to_fields=['id'])
+        new_field.set_attributes_from_name('author')
+        with connection.schema_editor() as editor:
+            editor.add_field(BookForeignObj, new_field)
+
     def test_creation_deletion_reserved_names(self):
         """
         Tries creating a model's table, and then deleting it when it has a