start transaction;
select id,rname,free_course_ph,cmp_id,free_date_limit_ph from ebk_students WHERE cmp_id=1105 and free_course_ph>0;
UPDATE ebk_students SET free_date_limit_ph=1561824000 where cmp_id=1105 and free_course_ph>0;

　确认没有问题，Commit；有问题，Rollback

COMMIT;