title: about "binary" datatypes
body: <p>I usually don't post noob questions but.... I am missing something since I began programming. </p>
  
  <p>Let's imagine a pojo entity object, with several properties name, description and so on. One of these is "direction" which can only be "IN" or OUT. </p>
  
  <p>What's the best data type for that property? 
  I could use a Boolean, assuming for example true as in and false as out. Or maybe I can use a single char 'I' and 'o', or an "enum".. </p>
  
  <p>Consider I will use this object with hibernate, the property will go on a table's column. So... What's the best data type for the column, too?</p>
  
  <p>Thank you</p>