How to attached or restore database with only with mdf file ?

create database my_db (name =my_name,
                                     file_name ='d:\data\my_db.mdf,
                     on log (name =my_log,
                               file_name ='d:\log\my_log.ldf) for attach_rebuildlog .

the parameter attached_rebuild_log create a new log file for database in defined location