i have accidentally deleted my own admin username. how can i restore.

If you don't have a database backup you can't.

i had a test user in my database. i changed its right to admin through my sql. that helped

If you have another admin user, he can re-create it. That should be the case if you were allowed to delete the admin. Whichever user had the most rights is now the admin.

If not you will have to go through the drop the admin table recovery as in the troubleshooting guide on forgotten passwords.

Maybe I misunderstood the question then: I was referring to as "not possible" that a deleted database entry is deleted and there is not trash to get it back. Of course re-creating a similar account is possible.

thanks, perhaps the term "restore" i used caused some confusion.