IBM DB2 4.3 Deploying C/C++ applications

154 DB2 Deployment Guide

4.3 Deploying C/C++ applications

C and C++ are probably two of the most popular and well-known programming

languages. They are general purpose programming languages developed in the

1970’s. The prevalence of these two languages still continues today on almost all

operating systems even though Java and other languages have achieved great

success.

DB2 provides various sets of APIs for C/C++ programmer for their choices.

For users who are focusing on application development and accessing a DB2

database from applications, CLI and ODBC provide the programming interfaces

and use dynamic SQL statements as function arguments.

Another option is embedded SQL. It takes the advantages of both static and

dynamic SQL statements to access the database. Embedded SQL statements

are placed in the host programming languages and therefore an additional

procedure called precompilation is required. Precompilation transforms the

embedded SQL statements into the host language function calls which are

recognizable codes for the host language compiler. Not only C and C++, but also

COBOL, FORTRAN, and REXX are supported host languages for the embedded

programming.

There are other tasks which are critical for DB2 maintenance or administration,

such as instance start and stop, runstats and reorg, and so on. To perform these

administrative tasks against DB2, users can issue commands from CLP, invoke

SQL routines, or use DB2 Administrative APIs. DB2 Administrative APIs, also

known as DB2 APIs, are a set of callable interfaces that give the customer an

easy way to administer DB2 from a programming language. It could be used

together with either CLI and ODBC, or embedded SQL.

In this section, we discuss an approach to bundle an application and the IBM

Data Server Driver for ODBC and CLI in a single package. This package can

then be a deployed to other systems. The operating system that our procedure is

based upon is either Linux or UNIX.

Before getting to the sample application and deployment script, we first discuss

some background and considerations for CLI and ODBC applications.

DB2 Call Level Interface (DB2 CLI) is IBM’s callable SQL interface to the DB2

family of database servers. It is a C and C++ programming interface. DB2 CLI is

based on the Microsoft Open Database Connectivity (ODBC) specification and

the International Standard for SQL/CLI. These specifications are the basis for