Altering column positions in MySQL

If I do something like in SQL :

ALTER TABLE `portal_portal` CHANGE `username` `username` VARCHAR(250) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL AFTER `customer_id`;

will it, in any way, effect my migrations since I’m not changing my ?

It affects how your database works.
If you recreate the database, you’re going to need to manually do this step. And it’s going to be hard to track down issues regardind this change.
I recommend that you add this a custom RunPython migration.

But all I want is to re-order the columns - hence AFTER customer_id` - so assumed that the re-ordering is not tracked in Django’s system.

This is a Django forum. I’m replying based on what you can do with django to achieve this result.
If this does not affect any performance, or how your database works, i wouldn’t do the migration. But if this is important for the business, i would create a migration for that.