implementing watchlist using checkbox and listview

I have a listview which is populated using a simplesearch. I had the idea of adding a watchlist feature using a checkbox, which is checked if the user has watchlisted any of the content items (e.g., a particular artist). Watchlist status is a boolean with the content ID and user ID as an identifier. I cannot figure out how to query watchlist status using the simplesearch's content item ids. The only thing that comes up is in the below snapshot. Has anyone had this issue of wanting to take data from a listview and do another query with the results?

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