Servlets using JDBC or SQLj

  Enterprise JavaBeans (EJB) using JDBC or SQLj

DB2 UDB provides an implementation of the two standard based Java 

programming interface (APIs), Java Database Connectivity (JDBC), and 

embedded SQL for Java (SQLj). This section provides an overview of JDBC, 

SQLj, and the conversion of existing MySQL Java applications to DB2 UDB.

MySQL has an optional package MySQL Connector/J, which is a type 4 JDBC 

driver. The latest Version of MySQL Connector/J implements SUN's JDBC 3.0 

API for relational database access.

Java database connectivity (JDBC)

JDBC is a vendor neutral dynamic SQL interface that provides data access for 

your application through standardized Java methods. JDBC drivers provide the 

mechanics to the JDBC API to allow Java applications to access databases. 

Currently JDBC API is in its third revision, but most of the drivers available in 

market comply to JDBC1.2 or JDBC2.0 specification. IBM DB2 V8.1 supports 

JDBC2.1 and some methods support JDBC3.0 forms.

A JDBC application can establish a connection to a data source using the JDBC 

DriverManager interface. In the following sections we discuss what are the 

changes required in Java application code from MySQL to DB2.

IBM JDBC driver for DB2

IBM DB2 UDB provides support for various types of JDBC technology enabled 

drivers. The drivers available in DB2 UDB V8.1 are:

DB2 JDBC type 2 driver

The DB2 JDBC type 2 driver, also called the 

native API/partly Java driver

, 

lets Java applications make JDBC calls that are translated to Java native 

methods. The Java applications that use this driver must run a DB2 client, 

which is used to communicate the JDBC requests to the DB2 server. 

Figure 7 1 shows a call transfer for DB2 JDBC type 2 driver. As shown in 

Figure 7 1, this driver can be used only by Java applications. This driver is 

implemented using the DB2 CLI interface to communicate with DB2 UDB 

servers.

For using DB2 JDBC type 2 driver you need following properties:

drivername= COM.ibm.db2.jdbc.app.DB2Driver 

URL= java:db2:dbname 

The user ID and password are implicitly picked from the DB2 client setup.

 Chapter 7. Application porting 

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