Creating query that returns id if condition is matched in rows from two tables

Question

I\'m learning SQL/dbms and using Postgres. I want to return rows that both have a certain value in a certain column. For example in tables Carpets and Curtain

Answer 1

If you want the result for matching in two table, then try this:

select id
  from curtains
      ,carpets
  where curtain.color = carpets.color;

This will return id where curtain.color = carpets.color