increment function in plsql varchar2

Question

I want use this in a varchar2. Ex.:

declare
  num number := &Number;
  serie varchar2(200) := 'S = ';
begin
  for x in 1 .. num loop
    serie += x, ' + ';
  end loop; `
end;
/

In the end I want that the serie be like "S = 1 + 2 + 3 ..." How can i make that work?

Answer 1

That would be something like this:

SQL> set serveroutput on
SQL> declare
  2    num number := &Number;
  3    serie varchar2(200) := 'S = ';
  4  begin
  5    for x in 1 .. num loop
  6      serie := serie || to_char(x) || ' + ';
  7    end loop;
  8
  9    -- remove the trailing "+"
 10    serie := rtrim(serie, ' +');
 11    dbms_output.put_Line(serie);
 12  end;
 13  /
Enter value for number: 5
S = 1 + 2 + 3 + 4 + 5

PL/SQL procedure successfully completed.

SQL>

A few comments:

• line 6: you have to concatenate (concatenation operator is a double pipe sign, ||) previous value of SERIE; otherwise, you'd have only the last number in it
• line 10: remove the trailing "+" sign