ruby on rails - Where query with uniqueness -

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i want query answers correct = true , grab 1 answer if have same question id. trying uniq or distinct.

@answers = answer.where(id: params[:answer_ids]) @correct_answers = @answers.where(correct: true, question_id: distinct).count

how grab 1 answer of answers same question_id?

try this:

@answers = answer.joins(:question).where(id: params[:answer_ids]) @correct_answers = @answers.where(correct: true).distinct(:question_id)

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