Help with delete

repair_tickets and rp_parts are HABTM.

If I do:

repair_ticket1.rp_parts

=> [#<RpPart id: 1, ...">, #<RpPart id: 1,...">, #<RpPart ...">]

I only want to delete one of those RpPart id:1, and not both of them. Is
it possible? How can I do that?

If you want to remove duplicates from your array you do

repair_ticket1.rp_parts.uniq!