What is the best way to do validation when adding data to mysql?

Question

PHP

There is data that needs to be reviewed after each save, for example, this is a user access table. After the moment you click "Save", you need to re-check if each of the records is in the table.
Option 1: select all records belonging to object A, add necessary / delete unnecessary ones.
Option 2: delete all records belonging to object A, add all new ones.
Now I'm planning "option 2". What's better?

Answer 1

Add field `updated` TINYINT(1), add UNIQUE KEY (`user_id`, `obj_id`).
Before changing, reset the flag:
When changing, we mark the added / duplicated entries:

INSERT INTO `table` (`user_id`, `obj_id`, `updated`) VALUES ($uid, $oid, 1)
    ON DUPLICATE KEY UPDATE `updated` = 1

After the change, delete the unmarked entries:

DELETE FROM `table` WHERE `user_id` = $uid AND `updated` = 0

Answer 2

I have a similar situation with a linking category table.
Personally, my option is to delete and re-record, the first option will take more resources, which is not very good

Answer 3

If such questions arise, then the structure for storing access rights is incorrectly selected.
If there is nothing to fix, yes, option 2 is less expensive. Less checks.
But, the recommendation is still to change the storage structure