How should the migration work?

Question

Database migration

Hello! Please tell me how the migration should work in this case:
There is a migration that adds three text values: test1, test2, test3 to the items table.
At the beginning of the migration, there is only 1 entry in the table.
I start the migration, the test1 record is already used in the items table, as I understand it, only test2, test3 have been added.
After migration, there are already 3 records in the table, everything is ok.

Now I am doing a reverse, in the migration it is described to delete test1, test2, test3 (those fields that were added).
The migration is taking place and there are now 0 records in the database.

Did this work correctly or how to do it, tell me, please.