It’s always good to know how any language handles and propagates exceptions, Oracle PL/SQL being no different. They’re plenty of examples online about raising and handling exceptions on the web, but one thing you may not have realized is how PL/SQL propagates exceptions that occur in the variable declaration section of a procedure.

In the first example I created a procedure that has a variable, l_var, which can handle one character. As expected, when I assign more then one character an exception is raised and is propagated to the EXCEPTION block of the procedure.

SQL> CREATE OR REPLACE PROCEDURE sp_test(p_var in varchar2)
  2  AS
  3    l_var VARCHAR2(1);
  4  BEGIN
  5    dbms_output.put_line('***START***');
  6    l_var := 'abc';
  7  exception
  8    WHEN others THEN
  9      dbms_output.put_line('***Exception***');
 10      raise;
 11  END sp_test;
 12  /
Procedure created.
SQL> exec sp_test(p_var => 'abc');
BEGIN sp_test(p_var => 'abc'); END;
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at "ODTUG.SP_TEST", line 10
ORA-06512: at line 1

Continue reading on my blog for the next example…