That's what I meant by this I wrote earlier >>>"You will have to write condition after first where condition based on what you're choosing featured properties to be displyed?"
Btw, joins will help you out but a boolean column will ease out your task!
Just one thing...15,16 & 17 are just the id's of what should show. They shouldn't be part of the query.
The query needs to be...Display properties from the 'properties' table if their ID is in the property_id column of the 'featured' table
Hope this makes sense!