I've been playing with NCHAR datatype for a little in oracle database. I created a table with column NCHAR(50) and then tried to inserted some chinese characters however when I pasted the characters SQL developer is not able to display it properly then when inserted on the column its not able to display it properly as well. The encoding in Environment -> Encoding is set to UTF-8 then NLS_CHARACTERSET and NLS_NCHAR_CHARACTERSET are set to AL32UTF8 and AL16UTF16 respectively. How come its still not printing properly?
I updated the encoding from Cp1252 before to UTF-8 and the NLS_CHARACTERSET and NLS_NCHAR_CHARACTERSET are already set to unicode then restarted the sql developer but still same thing.
Make sure you're using an editor display font that supports Chinese characters, here's your test -
Oracle SQL Developer is a Java swing application, everything is Unicode by definition.