Thanks in advance. I have a table set up something like this... this is greatly simplified to make the question easier to ask.
|id|hobby|person|enjoyment -------------------------- | |soccer|john|10 | |soccer|jake|5 | |baseball|john|3 | |baseball|nate|5 | |baseball|jordan|2 | |tennis|john|3 | |tennis|nate|7 | |chess|john|10 | |chess|nate|3 | |swimming|casey|6 Each person has a score of how much they enjoy a particular hobby. If they don't have a record in the database for a particular hobby, we assume they don't participate. Given 1 person, I need to know who at least participates in the most similar hobbies. In the above example, if I chose John, it should return Nate as (3) since they share 3 hobbies in common (baseball, tennis and chess), jake and jordan would both get (1) I could do this with multiple queries of course... SELECT hobbies FROM tblname WHERE person='john'; SELECT person FROM tblname WHERE hobbies='baseball' AND hobbies='tennis' AND hobbies='chess' AND name!='john' and keep doing that but it seems INCREDIBLY inefficient. I am certain there is a single optimized query to do this kind of stuff but it is WAY beyond me. Any ideas?
