Finding the Compromise – the Adapter Framework - Applied SOA Patterns on the Oracle Platform - page 423

for $sql in $query//*:Sql return
<java:Sql>{data($sql/text())}</java:Sql>
}
</urn:SQLStatements>
<urn:datasource>{$database}</urn:datasource>
</urn:executeSQL>
The complete SQL execution part is presented in the following screenshot, where
step 1 is the condition for our If branching, step 2 is the Assign operation, ex-
ecuting our single SELECT XQuery, and step 3 is the EJB Service Callout:
Maintaining the EJB service callout
10. Finally, in our Response flow, we generally have to replace CTUMessage/Payload
(body) with result of the Query execution.
That's all folks. In ten relatively simple (and most importantly—standard) steps, we cre-
ated a lightweight and very universal DB adapter, completely agnostic and suitable for
any Composition Controller. The main enabler of this technique is not the OSB's XQuery
engine or EJB, as they are absolutely standard and work exactly the same way on other
ESBs (RedHat FUSE or ServiceMix/CXF, for instance, where we have a similar approach
to Service Bean invocation from the XML blueprint, acting as an EP), but the Service Re-