title: Inserting national characters into an oracle NCHAR or NVARCHAR column does not work
body: <p>When inserting strings in an oracle database, some national characters are replaced with question marks, even though they are
  inserted in an NCHAR or NVARCHAR column - that should be able to handle all Unicode  characters.</p>
  
  <p>This happens using either Oracle's SQL Developer, sqlplus or using the JDBC driver.</p>
  
  <p>The database NLS_CHARACTERSET is set to WE8ISO8859P1   (western european iso-8859-1)
  The NLS_NCHAR_CHARACTERSET used for NCHAR columns is set to AL16UTF16. (UTF-16)</p>
  
  <p>Any character not in the NLS_CHARACTERSET seems to be replaced with a inverted question mark.</p>