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Alex Rivera
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After googling, browsing SO and reading , there doesn't seem to be a Rails-style way to efficiently get only those Parent objects which have at least one Child object (through a has_many :children relation). In plain SQL: SELECT * FROM parents WHERE EXISTS ( SELECT 1 FROM children WHERE parent_id = parents.id) The closest I've come is Parent.all.reject { |parent| parent.children.empty? } (based on another answer ), but it's really inefficient because it runs a separate query for each Parent .
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