Convert Unicode in Oracle database to Chinese with function unistr

example:

DECLARE
  V_EXT_DES   VARCHAR2(1000) := '\u5EE0\u5225\u4EE3\u865F';
  V_SQL       VARCHAR2(100);
  TEXT_BUFFER VARCHAR2(100);
BEGIN
  V_SQL := 'select unistr(REPLACE(''' || V_EXT_DES ||
           ''',''\u'',''\'')) from dual ';
  EXECUTE IMMEDIATE V_SQL
    INTO TEXT_BUFFER;
  DBMS_OUTPUT.PUT_LINE(TEXT_BUFFER);
END;