|Interface to Informix DBMS||Interface to Sybase DBMS|
This chapter describes how to use Oracle in this COBOL system and how to compile and link COBOL programs containing their code. It also describes the COBOL to Oracle integration package, explaining how to use it, as well as giving solutions to some common problems.
You can access the SQL functions offered by the database system from your COBOL program by embedding SQL statements in your COBOL programs using the following format:
EXEC SQL SQL_statement END-EXEC.
A preprocess step then replaces statements of the above form with the relevant calls to database services. Other additions are made to the source code to bind host COBOL variables to the SQL variable names known to the database system.
The advantage of embedding SQL in this way is that the programmer need not know the format of individual database routines. The disadvantage is that the resulting source code must be linked to the database routines, and therefore Animator using .int and .gnt code variants are unavailable. The COBOL to Oracle integration package described later in this chapter overcomes this limitation, but the source code used by Animator is the output from the precompiler rather than the original Embedded SQL written by the programmer. This disadvantage can be overcome by using the COBSQL integrated preprocessor (see the chapter Using COBSQL).
Please consult on disk documentation for information about the compatibility of this COBOL System with the various database management systems and their precompilers.
There is a special version of Pro*COBOL available from Oracle which is XM aware for running on DOS. It is V1.3.1.08.
You can run your COBOL program containing Oracle code in .int or .gnt code format. To make Oracle calls accessible to COBOL programs in .int or .gnt code format, you must use the oralib interface module to resolve the calls from COBOL to Oracle.
The COBOL to Oracle integration package consists of:
|oralib.gnt||main integration library|
|oralib.cbl||source code for oralib|
|cbl2orad.obj||object file for linking with DOS|
|dos.lnk||sample link file for DOS|
Windows and OS/2:
For Windows and OS/2 oralib simply loads the appropriate Oracle DLL. Depending on the version of Oracle in use, you may have to edit and recompile oralib to make it load the correct DLL:
The file oralib.dle contains all the Oracle runtime routines for DOS.
You also need the following COBOL system files to use the Oracle database support:
* applic.cfg, applic.exe and applic.lbr
are user-defined names for the user
application configuration, executable and library files.
You also need the PRO*Cobol support files and SQL*Net or local database. See the documentation supplied with your Oracle product for details on the support files required.
On UNIX, you may animate and run .int and .gnt code by using a COBOL Run-time System that has been linked with the SQL run-time routines supplied by Oracle.
The Oracle installer builds a suitable RTS, called rtsora. The RTS may also be rebuilt by the command:
make -f $ORACLE_HOME/procob/lib/procob.mk rtsora
Linking COBOL programs containing Oracle code is described in the manuals supplied with Pro*COBOL by Oracle.
You can load a COBOL to Oracle Interface Module in any of the following ways:
This is the simplest way. This call must be made before any database access is attempted.
This Compiler directive forces the main module to automatically load the specified module.
With a built system, the application has a configuration (.cfg) file that specifies the programs that makeup the system. You can modify this .cfg file to preload the oralib module as the system is started.
See the section Using COBOL Configuration Files for further details on this method.
Note: If you use either of the first two methods, ensure that only the top-level program calls the oralib interface module. Do not compile a subprogram with the INITCALL directive.
If you are using the Build utility, you can load your oralib file from your application configuration file. To do so, you must add the following information to your .cfg file:
[APPLIC-STARTUP] APPLICATION-LIBRARY:applic.lbr INITIALIZATION-LIBRARY:TOOLS.LBR
[APPLIC-PROGRAMS] applic.lbr UTILS.LBR
applic.lbr is a user-defined name
for the user application library file.
To avoid potential problems when interfacing between COBOL and Oracle, you must take the following areas into consideration:
You do this by setting the /S RTS switch in the COBSW environment variable. There is no absolute value to use to resolve this problem. To determine the best value for your circumstances, we recommend you try a value of 20000 first and adjust this up or down as required. For details on the /S run-time switch, see your Object COBOL User Guide.
You can set this environment variable in your autoexec.bat file (on DOS or Windows) or your config.sys file (on OS/2) as follows:
The latest DOS precompiler for COBOL released by Oracle is 1.3.08. This is a special release which works with XM. Because Oracle programs can be memory-intensive, it is not practical to use the real mode support files.
To ensure that your program picks up the correct version of the Oracle support files, the oracle\pbin directory must appear on the path before the oracle\bin directory.
The first version of Pro*COBOL supported on 16-bit Windows is 1.6. This is actually a 32-bit application and so WIN32S must be installed on the machine where it is running. However, Pro*COBOL 1.6 thunks to 16-bit and will only run with the 16-bit version of COBOL.
The last version of Pro*COBOL supported on 16-bit OS/2 is 1.3. Later versions of Pro*COBOL only support 32-bit COBOL.
Pro*COBOL Version 1.7 for Windows NT is a 32-bit application and will only work with 32-bit COBOL.
Versions of Pro*COBOL later than 1.5 for OS/2 are 32-bit applications. These versions will only work with 32-bit COBOL.
On UNIX, all versions of Pro*COBOL and COBOL are 32-bit. Please refer to your Oracle documentation for the recommended version of COBOL to use with your version of Pro*COBOL.
This section describes issues you must consider when interfacing between COBOL and Oracle on DOS.
If you want to run your COBOL/Oracle application against a remote database, you should ensure that at least 300Kb of base memory is free. If you want to run the application against a local database, the amount of memory required to run correctly is likely to be more than that available in base memory.
COBOL programs on DOS need to be run under the memory manager XM. Similarly, when running under DOS, Oracle uses its own memory manager, SQLPME.
In older versions of this COBOL system, there was no way for Oracle to route a call out of XM. Current versions of Micro Focus COBOL and Oracle provide this support. You must use the versions of COBOL and Oracle, including a special version of Pro*COBOL, given in the section Software Requirements earlier in this chapter to obtain this support.
The special version of Pro*COBOL enables a user program running under XM to talk to SQLPME. By default both XM and SQLPME try to use all available memory. Therefore, to enable this facility, you must restrict the memory for both memory managers.
To allocate the amount of extended memory to be used by XM, you set the /Z XM switch. We recommend you set /Z to a value of 4096Kb. You can set this switch in your autoexec.bat file as follows:
To allocate the amount of extended memory to be used by SQLPME, you set the DYNAMIC_MEMORY environment variable We recommend you set this environment variable to a value of 6020Kb. You set this in the Oracle configuration file, config.ora, as follows:
The following restrictions apply when interfacing between COBOL and Oracle on DOS:
This section describes issues you must consider when interfacing between COBOL and Oracle on Windows.
You must install the Oracle Required Support Files for Windows on your machine. You must also ensure that these files are made available on the PATH.
It is important to ensure that the COBOL stack has been set up, or the call to allocate memory (usually the last C call of the expanded connect statement) will fail. This takes the form of a Protection Violation caused by Initapp in coblib.dlw.
There must sufficient system resources for Oracle to make its connection; otherwise, you could receive a 9241 error when trying to connect to the database. Specifically, you must take the following two areas into consideration:
and ensure that no environment variables start with "LOC".
See the documentation supplied with your Oracle system for details on setting this environment variable.
This section describes issues you must consider when interfacing between COBOL and Oracle on OS/2.
The Oracle Required Support Files must be installed
You must ensure that the Oracle .dll files are made available on the LIBPATH.
If you are running with a local database, you need to be aware of the following issues:
LCC-00100: internal error, argument 
ORA-01078: failure in processing system parameters
Try closing down some applications to get Oracle to startup. If this is not possible, then reduce the amount of memory required by Oracle by setting the required parameters in the config.ora file. See your Oracle DBA Guide for details on these parameters.
To overcome this problem, log in as the sqldba before running the install.sql program. This .sql file is held in the oracle database directory, oracle6\dbs.
Oracle uses .pco and .cob filename extensions. For the Micro Focus Copybook Preprocessor (CP) to resolve copybooks and include statements correctly, use the following COBOL Compiler directives:
osext (pco) copyext (cob,cpy,cbl)
You can use Workbench Organizer to create an Oracle project (see the chapter Configuring Your Organizer Desktop in your Workbench User Guide). Typical values are:
|Project name:||Oracle Demos|
|Directives:||osext(eco) copyext(cob,cpy,cbl) p(cobsql) p(cp)|
If you are using COBSQL you can use the cobsql.dir file to specify COBSQL directives. Typical values are shown below:
confirm cbl2ora cobsqltype=oracle-win cobsqlinclude=e:\ora7win\pro16\cob end-c anim=no comp5=yes
If you are using COBSQL in conjunction with the Oracle precompiler, you should bear in mind the following points.
If errors still occur when compiling, the Pro*Cobol directives need to be put into the ORACLE configuration file. By default, this resides in the %ORACLE_HOME%\%Pro*Compilers% directory where %ORACLE_HOME% is the ORACLE root directory, and %Pro*Compilers% is the directory the precompilers are installed into (for example pro16). This file is normally called pcccob.cfg and Pro*COBOL directives can be placed in here. This file would have the following directives:
The COBSQLINCLUDE directive would no longer be used.
COMMIT (WORK) RELEASE
ROLLBACK (WORK) RELEASE
When cancelling ORACLE sub programs, make sure that you either perform a COMMIT/ROLLBACK RELEASE before you cancel the sub-module (a CONNECT would have to be performed after the sub-module was cancelled), or use the following SQL statements in place of the above statements:
Note: The oraprot module has a ROLLBACK WORK RELEASE statement in it. This would have to be changed to a ROLLBACK WORK statement.
To get the maximum information from Pro*Cobol, set the Pro*Cobol directive xref=yes. This can be added to the Pro*Cobol configuration file, pcccob.cfg.
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|Interface to Informix DBMS||Interface to Sybase DBMS|