# File lib/tapkit/access/adapters/csv.rb, line 568
                def rows_hash_for_expr( expr )
                        rows_hash = {}
                        existed = rows(expr.entity.external_name)
                        existed.each do |row|
                                flag = true
                                expr.key_values.each do |key, value|
                                        unless row[key] == value then
                                                flag = false
                                        end
                                end
                                if flag == true then
                                        rows_hash[row] = expr.row
                                end
                        end
                        rows_hash
                end