WebLogic: The Definitive Guide

Rowsets

A rowset is a container for tabular data, encapsulating a number of rows that have been retrieved from a data source. Rowsets were introduced as a standard extension in JDBC 2.0. The javax.sql.RowSet interface extends the java.sql.ResultSet interface with support for additional capabilities, such as using a data source to populate the rowset and assigning listeners that can be notified when the rowset is manipulated.

WebLogic comes with its own implementation of a disconnected rowset, sometimes called a cached rowset. This rowset can be populated in two ways: either from an existing ResultSet or using an SQL query that is executed against a data source. The rowset then can be sent to some remote client, updated at the client’s end, and later returned to the server and synchronized with the underlying database. Because the population of the rowset and the synchronization of the rowset data with the database typically will occur in separate transactions, WebLogic provides a number of nifty optimistic concurrency features that you can employ to control the synchronization. You also can export the rowset and its metadata to an XML document and schema, respectively. Likewise, XML data can be imported into the rowset. WebLogic’s rowset implementation can be found in the weblogic.jdbc.rowset package.

To illustrate the features of WebLogic’s cached rowsets, we shall refer to a database table, stockitems, which is defined as follows:

CREATE TABLE stockitems ( id integer primary key, ...