Example: XML Export For Update

Here is an example of a constraint that calls the XML export method, and updates a database column with the result of the INVOKE statement.

Whenever a person is updated, the fact that this PERSON record is updated is stored in XML format in the XMLupdate column of the PERSON_XML_LOG table.

UPDATE     person_xml_log pxl

SET        pxl.XMLupdate =

(

     INVOKE     xml.export

     WITH

     SELECT     'Update' ExecutionType

     ,          *

     ,          OLD(*)

     FROM       person p

     WHERE      p.id = pxl.person_id

)

After an update of "John Smith" to "Johnny Smith", the XMLupdate column of the PERSON_XML_LOG table contains:

<Persons documentName="Persons">

    <PERSON ID="112" FAMILY_NAME="Smith" FIRST_NAME="John">

        <Update ID="112" FAMILY_NAME="Smith" FIRST_NAME="Johnny"/>

    </PERSON>

</Persons>

NOTES:

•The 'Update' execution type is only useful in constraints in combination with old values.

•The execution type is the same for all exported row elements.