Problem with my substitution variable.

Question

My substitution variables don't prompt properly now. It worked fine before, but I don't know what I did to it. Here is the test code:
set define on;
connect sys/&sysPassword @&instanceName as sysdba;
execute dbms_output.put_line('this is a test');
When I tried to execute above lines in sqlplus, it didn't prompt anything, but got following result instead:
SQL> set define on;
SQL> connect sys/&sysPassword@&instanceName as sysdba;
Enter value for syspassword: execute dbms_output.put_line('this is a test');
Enter value for instancename:
SP2-0306: Invalid option.
Usage: CONN[ECT] [logon] [AS {SYSDBA|SYSOPER}]
where <logon> ::= <username>[<password>][@<connect_string>] | /
SQL>
I remember when I used substitution variables before in sqlplus worksheet, it popup a dialog for input, but it doesn't anymore.
Any ideas about this issue? Or what setting could affect the behavior? Thanks in advance.

Answer 1

It would work only if you put these set of statements in a .SQL file and run that file at SQL*Plus prompt:
SQL> @the_sql_script_created_above.SQL