IBM Books

Administration Getting Started

Step 1. Running Applications

As a database administrator, you might need to set up an application to run against the database. There are certain steps you must perform, depending on the type of application to be run. This section covers the following topics:

In addition, you can use Lotus Approach with DB2. This is described in the Using Lotus Approach with DB2 booklet (provided in the product box with DB2).

Running DB2 Embedded SQL Programs

To run a database client application that was developed using the DB2 Software Developer's Kit and ensure it can successfully access a DB2 database, follow the steps below:

  1. Be sure that DB2 is started on the database server to which the application program is connecting. If it is not:

    1. From the Control Center, click mouse button 2 on the icon representing the DB2 instance you want to start, and select Start from the pop-up menu. If the instance is local, it is started automatically. If the instance is remote, the Attach window opens prompting you for a user ID and password.

  2. Bind the DB2 utilities and the embedded SQL applications to the database. If you will also run CLI/ODBC applications, you can bind the CLI/ODBC driver at this point as well. See the Quick Beginnings book for your server platform.

  3. Run the application programs.

Running CLI/ODBC Programs

The DB2 Call Level Interface (CLI) run-time environment and the ODBC driver are included with the DB2 Client Application Enabler. This is contained on the DB2 Client Pack CD-ROM or can be downloaded from the Web page at http://www.software.ibm.com/data/db2.

This support enables applications developed using ODBC and DB2 CLI APIs to work with any DB2 server. DB2 CLI application development support is provided by the DB2 Software Developer's Kit (DB2 SDK) which is part of the separately orderable DB2 Application Development Kit product.

Before DB2 CLI or ODBC applications can access DB2, the DB2 CLI packages must be bound on the server. Although this will occur automatically on the first connection if the user has the required authority to bind the packages, it is recommended that the administrator do this first with each version of the client on each platform that will access the server. See the Quick Beginnings manual for specific details.

The following general steps are required on the client system to give DB2 CLI and ODBC applications access to DB2 databases. These instructions assume that you have successfully connected to DB2 using a valid user ID and password. Depending on the platform many of these steps are automatic.

  1. Use the Control Center to add the remote system (if you have separate client and server machines) so that its instances and databases can be made known to the Control Center, then add the instances and databases for that system. (Your local system is represented by the icon labelled Local.) If you do not have access to this program you can use the catalog command in the command line processor.

  2. On all platforms other than OS/2 and Windows 3.1, the DB2 CLI/ODBC driver is automatically installed when the DB2 Client Application Enabler is installed, and therefore nothing needs to be done. On OS/2 and Windows 3.1 you must use the Install ODBC Driver icon to install both the DB2 CLI/ODBC driver and the ODBC driver manager.

  3. To access the DB2 database from ODBC:

    1. The Microsoft, Visigenic, or other ODBC Driver Manager must already be installed (this is done by default during the installation of DB2).

    2. The DB2 databases must be registered as ODBC data sources. The ODBC driver manager does not read the DB2 catalog information; instead it references its own list of data sources.

    3. If a DB2 table does not have a unique index then many ODBC applications will open it as read-only. Create a unique index for each DB2 table that is to be updated by an ODBC application. Refer to the CREATE INDEX statement in the SQL Reference. Using the Control Center you would alter the settings of the table, then click on the Primary Key tab and move one or more columns from the available columns list over to the primary key columns list. Any column you select as part of the primary key must be defined as NOT NULL.

  4. Various CLI/ODBC Configuration Keywords can be set to modify the behavior of DB2 CLI/ODBC and the applications using it.

  5. If you followed the above steps to install ODBC support, and added DB2 databases as ODBC data sources, your ODBC applications will now be able to access them.

For specific instructions see the Quick Beginnings manual for your platform.

Running Java Programs

You can use DB2 Java Database Connectivity (JDBC) support to run the following types of Java programs:

Java can also be used on the server to write user-defined functions, stored procedures, and table functions.

For further information on developing Java applications that access DB2 databases refer to the Web page located at http://www.software.ibm.com/data/db2/java/ and the Road Map to DB2 Programming.

Configuring the Environment

The following environment variables must be set to run Java programs:

OS/2, Windows 95 and Windows NT

UNIX (AIX, Solaris and HP-UX)
In the following settings instance_name is the home directory of the DB2 instance owner.

Java Applications

Start your application from the desktop or command line, like any other application. The DB2 JDBC driver handles the JDBC API calls from your application and uses the DB2 Client Application Enabler to communicate the requests to the server and receive the results.

Java Applets

Because Java applets are delivered over the Web, you treat them a bit differently than Java applications. You must install DB2 (server or client) on the same machine as your Web server, then install the Java Development Kit (JDK) Version 1.1 from Sun Microsystems on the server as well (refer to http://www.software.ibm.com/data/db2/java for details).

To run your applet, you need only a Java-enabled Web browser on the client machine. When you load your HTML page, the applet tag downloads the Java applet to your machine, which then downloads the Java class files, including the COM.ibm.db2.java.sql and COM.ibm.db2.jdbc.net classes and DB2's JDBC driver. When your applet calls the JDBC API to connect to DB2, the JDBC driver establishes separate communications with the DB2 database through the JDBC applet server residing on the DB2 server.

To run your applets, do the following:

  1. Start the DB2 JDBC applet server on your Web server by entering: 
    db2jstrt portno
    where portno is the number of the unused TCP/IP port that you specified in the DB2Applt.java file.

  2. On your client system, start your Web browser and load the HTML file that imbeds your applet.

[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]

[ DB2 List of Books | Search the DB2 Books ]