Question

I have three tables that are associated. A category contains options that user enter in values for, simplified in the following…

group
-----
id
name
active

option
------
id
group_id
name
active

user_option
-----------
id
opton_id
value
active

My question is what is the best way to handle situations where a group is deactivated. What I’ve done in the past is looked up option id’s where the group_id = the group id that is being deactivated. Then I take the list of returned id’s and deactivate the user_option like…

set active=0 where option_id in (list of ids)

Then I update option, then I update group.

I’m interested if there is a way to do this kind of thing with a trigger or cascade. I’ve never used either in MySQL and thought I’d see what the best approach to this problem is.

Answer 1

Adding the ON UPDATE CASCADE to the foreign key on the USER_OPTION.active column should be all that’s necessary to implement your desired functionality, per the documentation. Assuming a foreign key constraint is already in place, use:

ALTER TABLE 
MODIFY active FOREIGN KEY fk_name (active) REFERENCES OPTION(active) ON UPDATE CASCADE