text: 
  -- identify all passengers in cabins where the cabin name has different letter prefixes
  -- assume cabin prefixes are A to G plus T plus O
  
  select * from
  train
  where cabin in
      (
  		select distinct cabin
  		from
  		train
  		where charindex(' ',cabin,1) > 0 and
  		(
  			charindex('A',cabin,1) + 
  			charindex('B',cabin,1) +
  			charindex('C',cabin,1) +
  			charindex('D',cabin,1) +
  			charindex('E',cabin,1) +
  			charindex('F',cabin,1) +
  			charindex('O',cabin,1) +
  			charindex('G',cabin,1) +
  			charindex('T',cabin,1)
  		) > 1
  	)
  