Delete items unchecked from a form

Question

I have a list from query that populate checkboxes (checked) in a form.
However, when a user deselects some of the items from, I want them to be deleted from the database for that user.
Here is the ex: this is how the form looks like:
                                         Category
Item                                  80      626
1. HS # 1 (87)                   chk    chk
2. HS #2  (59)                   chk    chk
This is the list of items already n their preferences (db ids)
80|87,  626|87,   80|59,   626|59
Now from a form, if they deselect one of the items (80|87), I want it to be deleted from the database.
Like these, DELETE FROM ITEMS_TBL WHERE ITEM_ID = 80, Category_ID = 87
How can we do it? Can we check ListContains or something else?

Answer 1

Let's say your query contained 5 records, ID's 1-5.  When output, the user unselects ID 2 and 5.  When they submit the form, you want to delete IDs 2 and 5 right?  But since they are not selected, their IDs are not available in the FORM scope, correct?
What I would do is run the same query on submit, but add an addendum that uses a ValueList() on the FORM variable that holds the selected IDs.  Like:
SELECT
ids,
WHERE ids NOT IN (#FORM.ids#)
That would basically get you back a query of record IDs that are up for deletion.  Then you could run another query right after it that goes:
DELETE FROM tableName
WHERE IDs in (#ValueList( firstQueryName.ids )#)