8.2.3. Linking Oracle tables into OpenLink
Start the Virtuoso Web User Interface
Figure 8.13. Start
Select the "Conductor" link in the Left Frame and Login as the
Figure 8.14. Conductor
Select the "Databases" -> "External Data Source" -> "Data
Sources" tab menu items
Figure 8.15. Databases
Select the "Connect" button for the "ora10ma" Oracle DSN.
Figure 8.16. Connect
On successful connection Select the "Link Objects" button to
obtain a list of available tables
Figure 8.17. Link
Select all the tables that are part of the "HR" catalog.
Figure 8.18. Select all
Change the Catalog for each table to be "HR" using the "Set All"
Figure 8.19. Catalog
Ensure a primary key is assigned to all table that are to be
used in the EDM generation phase.
Figure 8.20. Primary
Select the "Link" button to link the selected tables into
Figure 8.21. "Link"
On completion of the Link process the tables will be displayed
in the "External Linked Objects" tab.
Figure 8.22. Completion
The linked tables can be queried by clicking on the hyperlink in
the "Local Name" column of the "External Linked Objects" tab above,
which loads the Virtuoso "Interactive SQL" interface with the
required SQL "Select" for retrieving the remote table data . We
shall use the "HR.ora10ma.COUNTRIES" table to demonstrate this.
Figure 8.23. Querying
Then click the "Execute" button to run the query and retrieve
the results from the remote table.
Figure 8.24. Execute
The tables can also be viewed as part of the Virtuoso "SQL
Schema Objects" under the "HR" catalog name.
Figure 8.25. SQL Schema
The Link process is now complete enabling the tables to be
queried as if part of the Virtuoso Schema.