UPDATE

device_hub/migrations/0008_farmdevice_device_catalogs.py

@@ -1,23 +1,51 @@
 from django.db import migrations, models
 
 
+def ensure_device_catalogs_m2m_table(apps, schema_editor):
+    FarmDevice = apps.get_model("device_hub", "FarmDevice")
+    through_model = FarmDevice._meta.get_field("device_catalogs").remote_field.through
+    existing_tables = set(schema_editor.connection.introspection.table_names())
+    if through_model._meta.db_table not in existing_tables:
+        schema_editor.create_model(through_model)
+
+
 def copy_sensor_catalog_to_device_catalogs(apps, schema_editor):
     FarmDevice = apps.get_model("device_hub", "FarmDevice")
-    for farm_device in FarmDevice.objects.exclude(sensor_catalog__isnull=True).iterator():
-        farm_device.device_catalogs.add(farm_device.sensor_catalog_id)
+    through_model = FarmDevice._meta.get_field("device_catalogs").remote_field.through
+    through_table = through_model._meta.db_table
+    farm_device_column = through_model._meta.get_field("farmdevice").column
+    device_catalog_column = through_model._meta.get_field("devicecatalog").column
+
+    with schema_editor.connection.cursor() as cursor:
+        for farm_device_id, sensor_catalog_id in FarmDevice.objects.exclude(sensor_catalog__isnull=True).values_list("pk", "sensor_catalog_id").iterator():
+            cursor.execute(
+                f"""
+                INSERT IGNORE INTO {schema_editor.quote_name(through_table)}
+                ({schema_editor.quote_name(farm_device_column)}, {schema_editor.quote_name(device_catalog_column)})
+                VALUES (%s, %s)
+                """,
+                [farm_device_id, sensor_catalog_id],
+            )
 
 
 class Migration(migrations.Migration):
+    atomic = False
 
     dependencies = [
         ("device_hub", "0007_devicecatalog_dynamic_fields"),
     ]
 
     operations = [
-        migrations.AddField(
-            model_name="farmdevice",
-            name="device_catalogs",
-            field=models.ManyToManyField(blank=True, related_name="composite_farm_devices", to="device_hub.devicecatalog"),
+        migrations.SeparateDatabaseAndState(
+            database_operations=[],
+            state_operations=[
+                migrations.AddField(
+                    model_name="farmdevice",
+                    name="device_catalogs",
+                    field=models.ManyToManyField(blank=True, related_name="composite_farm_devices", to="device_hub.devicecatalog"),
+                ),
+            ],
         ),
+        migrations.RunPython(ensure_device_catalogs_m2m_table, migrations.RunPython.noop),
         migrations.RunPython(copy_sensor_catalog_to_device_catalogs, migrations.RunPython.noop),
     ]