Euro-sign (and Greek) doesn't work even with nchar/nvarchar2

Question

This is something that has been blocking me for a few days now, and I'm running out of ideas.
Basically, the problem can be summarised as follows:
declare
    text nvarchar2(100) := 'Make €€€ fast!';
begin
  dbms_output.put_line( text );
end;And the output (both in SQL Developer and Toad) is:
Make ¿¿¿ fast!See, I was under the impression that by using nchar and nvarchar2, you avoid the problems you get with character sets. What I need this for is to check (in PL/SQL) what the length of a string is in 7-bit units when converted to the GSM 03.38 character set. In that character set, there are 128 characters: mostly Latin characters, a couple of Greek characters that differ from the Latin ones, and some Scandinavian glyphs.
Some 10 other characters, including square brackets and the euro sign, are escaped and take two 7-bit units. So, the above message takes 17 7-bit spaces.
However, if I make a PL/SQL function that defines an nvarchar2(128) with the 128 standard characters and another nvarchar2(10) for the extended characters like the euro sign (the ones that take two 7-bit units), and I do an instr() for each character in the source string, the euro sign gets converted to an upside-down question mark, and because the delta (the first Greek character in the GSM 03.38 character set) also becomes an upside-down question mark, the function thinks that the euro sign is in fact a delta, and so assigns a length of 1.
To try to solve it, I created a table with an nchar(1) for the character and a smallint for the number of units it occupies. The characters are entered correctly, and show as euro signs and Greek letters, but as soon as I do a query, I get the same problem again. The code for the function is below:
  function get_gsm_0338_length(
    text_content in nvarchar2
  ) return integer
  as
    v_offset integer;
    v_length integer := 0;
    v_char nchar(1);
  begin
    for i in 1..length(text_content)
    loop
      v_char := substr( text_content, i, 1 );
      select l
      into v_offset
      from gsm_0338_charset
      where ch = v_char;
      v_length := v_length + v_offset;
    end loop;
    return v_length;
    exception
      when no_data_found then
        return length(text_content) * 2;
  end get_gsm_0338_length;Does anybody have any idea how I can get this to work properly?
Thanks,
- Peter

Answer 1

Well, the person there used a varchar2, whereas I'm using an nvarchar2. I understand that you need the right codepage and such between the client and the database if you use varchar2, which is exactly the reason why I used the nvarchar2.
However, if I call the function from /Java/, it does work (I found out just now). But this doesn't explain why SQL Developer and Toad are being difficult, and I'm afraid that, because this function is part of a much bigger application, I'll run into the same problem.
- Peter