Issue with passing schema name as variable to sql file

Question

Hi,
I have a scenario wherein from SYS a Java process (Process_1) is invoking SQL files and executing the same in SQLPLUS mode.
DB: Oracle 11.2.3.0
Platform: Oracle Linux 5 (64-bit)
Call_1.sql is being invoked by Java which contains the below content:-
ALTER SESSION SET CURRENT_SCHEMA=&&1;
UPDATE <table1> SET <Column1> = &&1;
COMMIT;
@Filename_1.sql
Another process (Process_2) again from SYS user is also accessing Filename_1.sql.
The content of Filename_1.sql is:-
DECLARE
cnt NUMBER := 0;
BEGIN
  SELECT COUNT(1) INTO cnt FROM all_tables WHERE table_name = 'TEST' AND owner = '&Schema_name';
  IF cnt = 1 THEN
  BEGIN
    EXECUTE IMMEDIATE 'DROP TABLE TEST';
    dbms_output.put_line('Table dropped with success');
  END;
  END IF;
  SELECT COUNT(1) INTO cnt FROM all_tables WHERE table_name = 'TEST' AND owner = '&Schema_name';
  IF cnt = 0 THEN
  BEGIN
    EXECUTE IMMEDIATE 'CREATE TABLE TEST (name VARCHAR2(100) , ID NUMBER)';
    dbms_output.put_line('Table created with success');
  END;
  END IF;
End;
Process_2 uses "&Schema_Name" identifier to populate the owner name in Filename_1.sql. But Process_1 needs to use "&&1" to populate the owner name. This is where I am looking a way to modify Call_1.sql file so that it can accommodate both "&&1"  to populate owner name values in Filename_1.sql (with avoiding making any changes to Filename_1.sql).
Any help would be appreciated.
Thanks.

Answer 1

Bad day for good code. Have yet to spot any posted today... Sadly, yours is just another ugly hack.
The appropriate method for using SQL*Plus substitution variables (in an automated fashion), is as command line parameters. Not as static/global variables defined by some other script ran prior.
So if a script is, for example, to create a schema, it should look something as follows:
-- usage: create-schema.sql <schema_name>
set verify off
set define on
create user &1 identified by .. default tablespace .. quota ... ;
grant ... to &1;
--eof
If script 1 wants to call it direct then:
-- script 1
@create-schema SCOTT
If script 2 want to call it using an existing variable:
-- script 2
@create-schema &SCHEMA
Please - when hacking in this fashion, make an attempt to understand why the hack is needed and how it works. (and yes, the majority of SQL*Plus scripts fall into the CLI hack category). There's nothing simple, beautiful, or elegant about SQL*Plus scripts and their mainframe roots.