# File lib/tapkit/access/adapters/postgresql.rb, line 88
                def join_clause
                        if @join_entities.empty? then
                                return ''
                        end

                        clause = ''
                        semantic = "#@join_semantic JOIN"
                        @join_entities.each_with_index do |entity, index|
                                name    = entity[0].external_name
                                another = entity[1]
                                clause << "#{semantic} #{name} #{another} ON #{@join_on[index]} "
                        end
                        clause.chop!
                        clause
                end