Possible to declare variable on demand?

Question

Hi,
Using Oracle 9i. I am new to PL/SQL (coming from C#), I would like to know if it is possible to declare a variable close to the where it is used. For example, in the Execution block of the procedure, let's assume I want to do:
.. existing code ...
vTest integer;
vTest := 123;
.. existing code (continued) ...
Doing so, the procedure failed to compile. The only way I know so far is to declare the vTest integer; in the declaration block. Can you please let me know how to declare the variable in the body of the procedure?
Thanks in advance.

Answer 1

1) The line numbers are added by SQL*Plus as you enter code in order to make it easier to debug (i.e. when the error message says there is an error on line 15, it's much easier if SQL*Plus has added line numbers than if you have to manually count them). They are not intended to be part of the code block.
2) Having nested DECLARE ... BEGIN ... END blocks in a piece of code would certainly strike me as unusual. Much like nested procedure declarations-- they are syntactically legal, and very occasionally useful, but they are sufficiently unusual that I would tend to avoid them if only because they are likely to confuse future developers that come along later. I've personally never seen code that did this in production, though I have seen a handful of folks use nested procedures, i.e.
CREATE PROCEDURE p1
AS
  PROCEDURE p2
  AS
  BEGIN
    NULL;
  END p2;
BEGIN
  p2;
END;I believe Tubby's point is that while it is good in general to declare variables close to where they are being used, if you have small modular code, the variable declaration block of your procedure ought to be very close to where the variable is being used. If you have a procedure that fills multiple pages and has multiple PL/SQL blocks, it is very likely that you should have factored out most of that code into smaller procedures and put everything in a single package.
Justin