Howto check substitution variable in sqlplus

Question

Hi all,
Is there a way to pass a parameter to a sql script (&1) and set a default if the parameter was not passed.
This should be possible without sqlplus asking for OBJECT_OWNER at runtime.
Something like IFDEF would be fine ;-)
DEFINE OBJECT_OWNER = nvl(&1,'OO')
PROMPT Run for schema: &OBJECT_OWNER
thanks for your help
chris

Answer 1

Frank Kulash wrote:
Hi,
I don't think there's any good way.
You can SPOOL the results of DEFINE, and then parse the output file to see if it contains a given variable name.
The following should set &got_variable to 'Y' or 'N', depending on whether &1 is defined or not:
SPOOL  define_output.lst
DEFINE
SPOOL     OFF
COLUMN     got_variable_col     NEW_VALUE     got_variable
SELECT     CASE
          WHEN  REGEXP_LIKE ( Q'[
@define_ouptut.lst
                      , '^DEFINE 1 *='     -- or put any variable name in place of 1
          THEN  'Y'
          ELSE  'N'
     END             AS got_variable_col
FROM     dual;I haven't test this.
Edited by: Frank Kulash on Oct 30, 2009 6:58 AMNo that won't work, SQL*PLUS commands (the '@') cannot be used inside a SQL statement or PL/SQL block.
Since SQL*PLUS is not designed to have any flow control, best approach may be to use named substitution variables and a more formal usage pattern:
Create initialization script(s) that define all the substitution variables and sets them to their default values.
Create completion script(s) the undefine all the substitution variables.
Any user of your script system must call the initialization script(s) first.
Then if they want to override defaults, they redefine the variable.
Then they call the script(s) that do the interesting stuff. The scripts only use the named variables.
When done, call the completion script(s) to clean up.