Refs #32502 -- Avoided table rebuild when removing fields on SQLite 3.35.5+.

ALTER TABLE ... DROP COLUMN was introduced in SQLite 3.35+ however
a data corruption issue was fixed in SQLite 3.35.5.

2 files changed, 12 insertions, 0 deletions

diff --git a/django/db/backends/sqlite3/features.py b/django/db/backends/sqlite3/features.py
index d0c9dc5391..9161ae3133 100644
--- a/django/db/backends/sqlite3/features.py
+++ b/django/db/backends/sqlite3/features.py
@@ -28,6 +28,8 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_case_insensitive_like = True
     # Is "ALTER TABLE ... RENAME COLUMN" supported?
     can_alter_table_rename_column = Database.sqlite_version_info >= (3, 25, 0)
+    # Is "ALTER TABLE ... DROP COLUMN" supported?
+    can_alter_table_drop_column = Database.sqlite_version_info >= (3, 35, 5)
     supports_parentheses_in_compound = False
     # Deferred constraint checks can be emulated on SQLite < 3.20 but not in a
     # reasonably performant way.
diff --git a/django/db/backends/sqlite3/schema.py b/django/db/backends/sqlite3/schema.py
index 18449026bd..b3a2f4282b 100644
--- a/django/db/backends/sqlite3/schema.py
+++ b/django/db/backends/sqlite3/schema.py
@@ -18,6 +18,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         "REFERENCES %(to_table)s (%(to_column)s) DEFERRABLE INITIALLY DEFERRED"
     )
     sql_create_column_inline_fk = sql_create_inline_fk
+    sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
     sql_create_unique = "CREATE UNIQUE INDEX %(name)s ON %(table)s (%(columns)s)"
     sql_delete_unique = "DROP INDEX %(name)s"
 
@@ -400,6 +401,15 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
             if field.remote_field.through._meta.auto_created:
                 self.delete_model(field.remote_field.through)
             # For explicit "through" M2M fields, do nothing
+        elif (
+            self.connection.features.can_alter_table_drop_column
+            # Primary keys, unique fields, and foreign keys are not
+            # supported in ALTER TABLE DROP COLUMN.
+            and not field.primary_key
+            and not field.unique
+            and not (field.remote_field and field.db_constraint)
+        ):
+            super().remove_field(model, field)
         # For everything else, remake.
         else:
             # It might not actually have a column behind it