Oracle apex select list and hide values

问题

I have scenario that allow the student to choose desire of majors by defining three select list. I have three majors : CS , IT and IS. For example if the student In the first desire he chosen CS from select list then in the second select list the CS major I want it don't appear in the list . For the second select list if he chosen IT then IT don't appear in the third desire where the last select list will contain only IS .

is there any idea how can I do this scenario ?

Thanks

回答1:

One option is to use Cascading List of Values and set previous items as "Parent item(s)". Query for every subsequent select list item would remove previously chosen values, e.g.

select subject_name d,
       subject_id r
from subjects
where subject_id not in (:P1_FIRST_MAJOR, :P1_SECOND_MAJOR);

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However, why wouldn't you use a Shuttle item instead? Offer all subjects and let the student select any of them, simply by moving them from the left to the right side of the shuttle item?

来源：https://stackoverflow.com/questions/64191916/oracle-apex-select-list-and-hide-values