text: -- SQL
  -- 3. Show address information for each person, but ONLY keep the LATEST address information for each person.
  
  select people.name, max(address.updatedate)
  from address
  inner join people
  on people.id= address.id
  group by people.name;
  
  
  
  -- results:
  --
  -- B	2015-11-01
  -- C	2016-12-01
  -- D	2015-04-27
  -- A	2016-09-02
  