How to get not exists set in collection in Rails -


i wanna set doesn't exists in collection. following:

ids = [1,2,3,4,5] # 2,3,4 not exists user.where(:id => ids)

i want set [2,3,4]

without affecting performance,have solution?

use following:

ids - user.where(id: ids).select(:id).map(&:id)

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