Mysql query to find all rows that have the same values as another row

Question

My database contains rows that generally look like:

PersonItem
__________
id
personId
itemId

╔════╦══════════╦════════╗
║ ID ║ PERSONID ║ ITEMID ║
╠════╬═══         


        

Answer 1

Something like this should do the trick:

SELECT P1.*
FROM PersonItem P1
INNER JOIN PersonItem P2 ON P2.ID <> P1.ID
AND P2.PersonId = P1.PersonId
AND P2.ItemId =   P1.ItemId