Yep, I've never done it, but I've definitely been aware of how easy it can happen. When I'm in this kind of situation on a production DB without easily restora

Yep, I've never done it, but I've definitely been aware of how easy it can happen. When I'm in this kind of situation on a production DB without easily restorable backups I usually try to remember to put all my delete/update queries in a transaction. Then commit after I see the appropriate number of rows have been effected.