74088ac949
The order of the array before being shuffled needs to be the same if we want to have the same array after being shuffled with a certain seed. We were using `pluck(:id)`, which doesn't guarantee the order of the elements returned. Replacing it with `order(:id).pluck(:id)` adds an `ORDER BY` clause and so guarantees the order of the elements.
17 lines
462 B
Ruby
17 lines
462 B
Ruby
module Randomizable
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extend ActiveSupport::Concern
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class_methods do
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def sort_by_random(seed = rand(10_000_000))
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ids = order(:id).pluck(:id).shuffle(random: Random.new(seed))
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return all if ids.empty?
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ids_with_order = ids.map.with_index { |id, order| "(#{id}, #{order})" }.join(", ")
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joins("LEFT JOIN (VALUES #{ids_with_order}) AS ids(id, ordering) ON #{table_name}.id = ids.id")
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.order("ids.ordering")
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end
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end
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end
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