Need info on "DEFINE" keyword

Question

I need information on the DEFINE keyword on plSQL. There is a package which has definitions as below
DEFINE A = &1
DEFINE B = &2
DEFINE C = &3
Begin
End;/
The data for this being substituted through a .bat file whose content is as below
sqlplus wedb/wedbo@ORACLE1 @D:\test\test1\auto_run.sql WS Y OE
pause
So I need information on how to pass "NULL" value on this last parameter C, Thank you

Answer 1

For cases like this I use "script launcher":
C:\>type c:\temp\sqlplus_script_launcher.sql
DEFINE  S="&1"
DEFINE  1=''
DEFINE  2=''
DEFINE  3=''
DEFINE  4=''
DEFINE  5=''
DEFINE  6=''
DEFINE  7=''
DEFINE  8=''
DEFINE  9=''
DEFINE 10=''
DEFINE 11=''
DEFINE 12=''
DEFINE 13=''
DEFINE 14=''
DEFINE 15=''
DEFINE 16=''
DEFINE 17=''
DEFINE 18=''
DEFINE 19=''
DEFINE 20=''
@&sNo assume I have a script:
C:\>type c:\temp\x.sql
DEFINE A="&1"
DEFINE B="&2"
DEFINE C="&3"
SET NULL "This value is NULL"
COLUMN C FORMAT A20
SELECT '&A' A,'&B' B,'&C' C FROM DUAL
EXITTo execute x.sql I would use "script launcher":
C:\>sqlplus scott/tiger @c:\temp\set_null_params "c:\temp\x WS Y OE"
SQL*Plus: Release 10.2.0.1.0 - Production on Sat Oct 25 10:20:38 2008
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
old   1: SELECT '&A' A,'&B' B,'&C' C FROM DUAL
new   1: SELECT 'WS' A,'Y' B,'OE' C FROM DUAL
A  B C
WS Y OE
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Pr
oduction
With the Partitioning, OLAP and Data Mining options
C:\>sqlplus scott/tiger @c:\temp\set_null_params "c:\temp\x WS Y"
SQL*Plus: Release 10.2.0.1.0 - Production on Sat Oct 25 10:20:42 2008
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
old   1: SELECT '&A' A,'&B' B,'&C' C FROM DUAL
new   1: SELECT 'WS' A,'Y' B,'' C FROM DUAL
A  B C
WS Y This value is NULL
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Pr
oduction
With the Partitioning, OLAP and Data Mining options
C:\>There is also a way to define SQL*Plus substitution variable if it is not defined and leave substitution variable value as is if it is defined. It is posted in Russian Edition of Oracle Magazine August/September 2003 issue, so you will need google translator, or simply look for NVL.SQL script.
SY.