debian-mirror-gitlab/app/models/concerns/from_set_operator.rb
2020-11-24 15:15:51 +05:30

19 lines
754 B
Ruby

# frozen_string_literal: true
module FromSetOperator
# Define a high level method to more easily work with the SQL set operations
# of UNION, INTERSECT, and EXCEPT as defined by Gitlab::SQL::Union,
# Gitlab::SQL::Intersect, and Gitlab::SQL::Except respectively.
def define_set_operator(operator)
method_name = 'from_' + operator.name.demodulize.downcase
method_name = method_name.to_sym
raise "Trying to redefine method '#{method(method_name)}'" if methods.include?(method_name)
define_method(method_name) do |members, remove_duplicates: true, alias_as: table_name|
operator_sql = operator.new(members, remove_duplicates: remove_duplicates).to_sql
from(Arel.sql("(#{operator_sql}) #{alias_as}"))
end
end
end