Enterprise J2ME Developing Mobile Java Applications [Electronic resources] نسخه متنی

11.8 IBM DB2 Everyplace

DB2e is the lightweight device version of the popular DB2 database. In this book, we cover DB2e v8.1. It runs natively on many platforms, including the Palm OS, Symbian OS, PocketPC, QNX, and embedded Linux. DB2e comes with a tool called Mobile Application Builder that allows developers to visually build DB2e applications.

Note

The Palm OS is not CDC-compatible and does not have standard JDBC support. But the IBM WebSphere Micro Environment (formerly known as J9) for Palm OS provides a JDBC extension. DB2e's JDBC driver works only on IBM's Palm OS Java runtime.

DB2e does not support stored procedures on devices. Its JDBC driver does not support the CallableStatement interface. DB2e supports only a subset of SQL types: INT, VARCHAR, BLOB, DECIMAL, CHAR, SMALLINT, DATE, TIME, and TIMESTAMP. The SQL statements supported by DB2e are listed in Table 11.2. It does not support advanced SQL features such as table JOINs. DB2e supports encrypted data fields and table storage optimization features. We can use the following code snippet to connect a local DB2e database.

Class.forName("com.ibm.db2e.jdbc.DB2eDriver");
Connection conn = DriverManager.getConnection("jdbc:db2e:mydb");
// SQL queries and updates etc.
// ... ...

In addition to the JDBC interface, DB2e also supports C/C++ native interfaces through the Call-Level Interface (CLI). DB2e is part of IBM's mobile strategy, and it plays well with other IBM mobile middleware tools such as the MQe, SMF, and WebSphere Studio Device Developer (see "Resources").