mysql event to change a fields value when a date is reached

Question

What I am trying to accomplish is this: I have table1 which contains user_id,group_id(int with a default value set) and expire_date.Also table2 which between others has a field user_group_id which serves as foreign key to group_id of table1.

When the date is reached I'd like to change values of group_id and user_group_id to default.

Unfortunately it seems I can't figure my way around this since I'm really new to mysql.

Table1 will contain like 500 rows max.Probably the event won't be used to update more than 4-5 rows per run.

Automated alternative solutions are welcome. mysql 5.2.7 php 5.3.8 CentOs 6

Thanks in advance for any responces!

Answer 1

Did it with event.

CREATE EVENT event_name2
  ON SCHEDULE 
   EVERY 24 HOUR
   DO
    UPDATE test.employees
    SET `group`=DEFAULT
    WHERE expire_date <= now( )

Firstly i thought to use triggers but they occur only when something is changed on database witch wasnt the case here.