48 lines
1.5 KiB
Ruby
48 lines
1.5 KiB
Ruby
# frozen_string_literal: true
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module FromSetOperator
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# Define a high level method to more easily work with the SQL set operations
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# of UNION, INTERSECT, and EXCEPT as defined by Gitlab::SQL::Union,
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# Gitlab::SQL::Intersect, and Gitlab::SQL::Except respectively.
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def define_set_operator(operator)
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method_name = 'from_' + operator.name.demodulize.downcase
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method_name = method_name.to_sym
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raise "Trying to redefine method '#{method(method_name)}'" if methods.include?(method_name)
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define_method(method_name) do |*members, remove_duplicates: true, remove_order: true, alias_as: table_name|
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members = flatten_ar_array(members)
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operator_sql =
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if members.any?
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operator.new(members, remove_duplicates: remove_duplicates, remove_order: remove_order).to_sql
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else
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where("1=0").to_sql
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end
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from(Arel.sql("(#{operator_sql}) #{alias_as}"))
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end
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# Array#flatten with ActiveRecord::Relation items will load the ActiveRecord::Relation.
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# Therefore we need to roll our own flatten method.
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unless method_defined?(:flatten_ar_array) # rubocop:disable Style/GuardClause
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define_method :flatten_ar_array do |ary|
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arrays = ary.dup
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result = []
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until arrays.empty?
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item = arrays.shift
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if item.is_a?(Array)
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arrays.concat(item.dup)
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else
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result.push(item)
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end
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end
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result
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end
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private :flatten_ar_array
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end
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end
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end
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