title: Using IN operator in SQL
body: <p>Suppose I have the database consisting of T1 (a, b, c)
  And I also have the database T2 (a, b, c)
  Can I use the IN operator to check that there is a record from T1 to T2?
  Like this for example:</p>
  <pre>
  select a
  from T1
  where (a, b, c) in (select a, b, c
                      from T2)
  </pre>
  <p>Or does the IN operator only work on a single value?
  Thanks for answering :)</p>