For access to relational databases, applications use the Java™ Database Connectivity (JDBC)
drivers and data sources that you configure for the application server.
Before you begin
Each vendor database requires different JDBC driver implementation classes for JDBC
connectivity. A JDBC provider encapsulates those vendor-specific driver files. Through the data
source that you associate with the JDBC provider, an application server obtains and manages the
physical connections for transactions between applications and the database. Attention: If you are accessing a DB2® database, IBM Optim pureQuery
Runtime is an alternative to JDBC. For more information on pureQuery, see the topic, Task overview:
IBM Optim pureQuery Runtime, in the related links section.
Before you start this task,
determine the version of data source that you need according to the API specification of your
applications.
- Data sources (WebSphere® Application Server
Version 4) are for use with the Enterprise JavaBeans
(EJB) 1.0 specification and the Java Servlet 2.2
specification.
- Data sources of the latest standard version are for use with applications that implement the
more advanced releases of these specifications.
Important: If you connect to DB2 for z/OS® through the JDBC Universal JDBC Driver,
follow the steps that are outlined in the topic, Using the DB2
Universal JDBC Driver to access DB2 for z/OS. This article gives detailed instruction on installing the JDBC driver
and related files, plus activating required JDBC properties.
Procedure
- Verify that all of the necessary JDBC driver
files are installed on your node manager.
Consult the article,
Data source minimum required settings, by vendor for that information.
If you opt to configure a user-defined JDBC provider, check your database
documentation for information about the driver files.
- Create a JDBC provider.
When you create
a JDBC provider from the administrative console, see the topic, Configuring
a JDBC provider using the administrative console; or
Using the
wsadmin scripting client, see the topic, Configuring a JDBC provider
using the scripting; or
Using the Java Management
Extensions (JMX) API, see the topic, Creating a JDBC provider and
data source using the JavaManagement
Extensions API.
- Create a data source.
From the administrative
console, see the topic, Creating a data source using the administrative
console; or
Using the wsadmin scripting client, see the topic,
Configuring new data sources using scripting. For V4 data sources,
see the topic, Configuring new WAS40 data sources using scripting;
or
Using the JMX API, see the topic, Creating a JDBC provider
and data source using the JavaManagement
Extensions API.
Required properties: Different
database vendors require different properties for implementations
of their JDBC drivers. Set these properties on the WebSphere Application Server data source.
Because Application Server contains templates for many vendor JDBC
implementations, the administrative console surfaces the required
properties and prompts you for them as you create a data source. However,
if you script your data access configurations, you must consult the
article Data source minimum required settings, by vendor, for the
required properties and settings options.
- Optional: Configure custom properties.
Like the required properties, custom properties for specific
vendor JDBC drivers must be set on the application server data source.
Consult your database documentation for information about available
custom properties. To configure a custom class to facilitate the handling
of database properties that are not recognized natively by the Application
Server, refer to the topic, Developing a custom DataStoreHelper class.
There
are also optional data source properties, such as the DB2 sslConnection
custom property, that you might want to configure. Refer to the Application
Programming Guide and Reference for Java for
your version of DB2 for z/OS if you use the DB2 Universal JDBC Driver provider for more information
about these custom properties.
- Bind resource references to the data source. See the article,
Data source lookups for enterprise beans and web modules.
- Test the connection (for non-container-managed persistence
usage).
See the topic, Test connection service.
Results
If you use the DB2 JDBC
Universal Driver, you might experience data source failures that the
application server JVM log does not document. Check the DB2 database log or the WebSphere Application Server JDBC trace
log (if JDBC trace was active). You might find that a bad authentication
credential is the cause of failure. Currently the DB2 JDBC Universal Driver does not identify or
surface the errors that are produced by non-valid authentication credentials
in a proper or consistent way. Even if you receive information
about a bad credential, check the database and JDBC trace logs. These
logs provide more reliable, detailed error data on authentication
failures.
Best practice: The JDBC trace log exists only
if the JDBC trace service is active during server start up. Activate
the service in the administrative console. For more information, see
the topic, Enabling trace at server startup. Specify WAS.database as
the trace group and select com.ibm.ws.db2.logwriter as the
trace string.