SQL Select only rows where multiple relationships exist

Question

Given a parent table \'parent\'

╔═══════════╦══════════╗
║ PARENT_ID ║   NAME   ║
╠═══════════╬══════════╣
║         1 ║ bob      ║
║         2 ║ carol    ║
         


        

Answer 1

I just saw this solution to a different question that seems to fit this case:

 SELECT distinct parent_id
 FROM rel as T1
 INNER JOIN rel as T2
 ON T1.parent_id = T2.parent_id
 WHERE T1.prop_id = '1' and T2.prop_id = '5'