Static SQL - COBOL PRE-compile process
For COBOL-Static SQL program, program needs to be precompiled before doing actual
compilation of that program.
Following are the 4 steps to compile a COBOL-DB2 program
STEP 1 - DB2 PRECOMPILE Process
The DB2 Precompile performs three functions. First, it checks the SQL in
the program for errors. Second, it adds working storage areas and source
code compatible statements that are used to invoke DB2. One of the working
storage areas contains a literal "timestamp" called a consistency token.
Finally, all of the SQL statements are extracted from the program source
and placed into a member called the DataBase Request Module, or DBRM, which
also contains the consistency token.
STEP 2 - COMPILE
The modified source from the precompile is then compiled. The code is
checked for errors, and a compiled version of the code is created.
STEP 3 - LINK-EDIT
The compiled code is link-edited along with statically called source language
and DB2 run-time modules to create a Load Module. Imbedded in this
module is the same consistency token that was generated in the precompile.
If multiple DB2 programs are statically linked together, the resulting load
module contains a consistency token for each one.
STEP 4 - DB2 BIND
The bind process reads the DBRM that was created in the precompile and
prepares an access path to the data. This access path, along with the
consistency token, is stored in the DB2 catalog as a Package. Every Package
is bound into a Package List, or Collection. The name of the Collection is
specified by the PACKAGE parameter. A Collection is a group of Packages
that are included in one or more Plans. The QUALIFIER parameter of the
bind is used to direct the SQL to the specific set of DB2 objects (tables,
views, aliases or synonyms) qualified by this name.
EXECUTING COBOL-DB2 PROGRAM
When COBOL-DB2 Program executes, the plan name must be specified.
For online CICS programs, the plan name is specified by Tran ID in
the Resource Control Table (RCT). For a batch program, the plan name is
specified in the SYSTSIN input DD. The packages for all DB2 programs
executed under a Tran ID or batch job step must be included in collection
bound into this plan. When the first SQL statement of each program is
executed, DB2 searches the collections within the plan using the package name
and consistency token from the load module. If an exact match is not
found, a -805 SQLCODE is returned.
COBOL DB2 PROGRAMMING - Primary
SAMPLE COBOL DB2 COMPILE JCL
SAMPLE COBOL DB2 RUN JCL