Oracle® Database Programmer's Guide to the Oracle Precompilers 10g Release 2 (10.2) Part Number B14354-01 |
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This appendix looks at the improvements and new features offered by the Oracle Precompilers Release 1.8. Designed to meet the practical needs of professional software developers, these features will help you build effective, reliable applications.
With releases 1.5, 1.6, and 1.7 of the Oracle Precompilers, source files that FETCH
data into host variables without associated indicator variables return an ORA-01405
message at runtime if a NULL
is returned to the host variable. With release 1.8, when you specify MODE=ORACLE
and DBMS=V7
, you can disable the ORA-01405
message by also specifying UNSAFE_NULL=YES
.
When developing applications for the Oracle database version 7 Server, the preferred practice is to include indicator variables for any host variable that might have a NULL
returned to it. When migrating applications from Oracle Version 6 to Oracle database version 7, however, the UNSAFE_NULL
option can significantly ease the process.
For more information, see "UNSAFE_NULL" and "Using Indicator Variables".
Applications precompiled with DBMS=V6
maintain full compatibility with Oracle Version 6. When upgrading to Oracle database version 7, if you precompile with DBMS=V6
specified, your applications will be unaffected by the ORA-01405
messages.
Applications precompiled with MODE=ORACLE
and DBMS=V7
return the ORA-01405
error at runtime if a NULL
is returned to a host variable when there is no associated indicator variable. When upgrading to Oracle database version 7 with these options specified, you will need to migrate your applications in one of two ways:
Modify your source code to include the necessary indicator variables
Specify UNSAFE_NULL=YES
on the command line
If you are upgrading to Oracle database version 7 and use DBMS=V7
when precompiling, or if you intend to use new Oracle database version 7 features that are different from Oracle Version 6, in most instances, the change requires minimal modification to your source files. However, if your application may FETCH
null values into host variables without associated indicator variables, specify UNSAFE_NULL
=YES
to disable the ORA-01405
message and avoid adding the relevant indicator variables to your source files.
For information about precompile time messages associated with the UNSAFE_NULL
option, see Oracle Database Error Messages.