# File lib/jdbc_adapter/jdbc_postgre.rb, line 365 def distinct(columns, order_by) return "DISTINCT #{columns}" if order_by.blank? # construct a clean list of column names from the ORDER BY clause, removing # any asc/desc modifiers order_columns = order_by.split(',').collect { |s| s.split.first } order_columns.delete_if(&:blank?) order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" } # return a DISTINCT ON() clause that's distinct on the columns we want but includes # all the required columns for the ORDER BY to work properly sql = "DISTINCT ON (#{columns}) #{columns}, " sql << order_columns * ', ' end