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Using Cloudscape's Java Extensions
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Reference Manual |
Getting External Data: Using the Cloudscape Virtual Table InterfaceCloudscape comes with a powerful interface to external data. Called the Virtual Table Interface, or VTI, it provides a way for you to access data from some external data source within an SQL-J statement as if it were a real table. To access the data, you first must create a Java class that fulfills the VTI requirements (see Requirements and Options for Read-Only VTI Classes). Within the SQL-J language, you do not need to declare a VTI or create it as a database object. Instead, you construct a VTI dynamically using the NEW keyword, providing any parameters. In SELECT statements you also provide a correlation name for the virtual table. For example, the class COM.cloudscape.tools.FileImport is a class provided by Cloudscape for an import/export utility that fulfills the VTI requirements. (Cloudscape has also provided a built-in class alias for this class). Within an SQL-J statement, you use the NEW keyword to create a virtual table from data in a flat file (from which you can SELECT).
INSERT INTO emptyTable You can write your own classes to access any kind of external data, such as news feeds, data from other database vendors, etc. See Programming VTIs for more information. |
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![]() Cloudscape Version 3.6 For information about Cloudscape technical support, go to: www.cloudscape.com/support/.Copyright © 1998, 1999, 2000 Informix Software, Inc. All rights reserved. |