Commit b47ef04e authored by Chris Beaven's avatar Chris Beaven
Browse files

Fix any sqlite field migration deleting all implicit m2m tables 

Fixes #22281
parent cc5804bc

django/db/backends/sqlite3/schema.py

+8 −2
Original line number Diff line number Diff line
@@ -64,6 +64,9 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): 
        for field in delete_fields:

            del body[field.name]

            del mapping[field.column]

            # Remove any implicit M2M tables

            if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:

                return self.delete_model(field.rel.through)

        # Work inside a new app registry

        apps = Apps()

        # Construct a new model for the new state
@@ -87,8 +90,11 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): 
            ', '.join(self.quote_name(y) for x, y in field_maps),

            self.quote_name(model._meta.db_table),

        ))

        # Delete the old table

        self.delete_model(model)

        # Delete the old table (not using self.delete_model to avoid deleting

        # all implicit M2M tables)

        self.execute(self.sql_delete_table % {

            "table": self.quote_name(model._meta.db_table),

        })

        # Rename the new to the old

        self.alter_db_table(model, temp_model._meta.db_table, model._meta.db_table)

        # Run deferred SQL on correct table