Ruby on Rails ActiveRecord query to find single lines -


modela has_many modelb, , want find of modela have 1 modelb. came with

modelb.select('modela_id').group('modela_id').count

to number of occurence of each one, there nice ruby way list of modela_id count 1? or better way beginning?

try using having clause

modelb.select('modela_id').group('modela_id').having('count(modela_id) = ?', 1)

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