Without knowing your sample - are you sure you need a mapping at all?
In case you just want to show a distinct row of your table, you can also do the following:
Reuse the same Page source on toppage and subpage (the tree is really shared as long as you don’t use the option “Load Data|On Every page”, so no new loading of all records is done when entering the subpage)
When clicking the button, label or whatever control enters the subpage, save your unique row-key in a second tree before.
You can do this by using an “Update Node” action like:
Update Node(s): $CURRENTLY-EDITING/Root/@edit-id
with Result of: @id
In the subpage, you can select the wanted row by using that @edit-id as constraint.
E.g. you can define a repeatable table with following “Create for each item in” XPath setting:
$DB2/DB/RowSet/Row[ @id = $CURRENTLY-EDITING/Root/@edit-id]
Or if you don’t want to create a table but just a Label, you can set its text by using a similar XPath
$DB2/DB/RowSet/Row[ @id = $CURRENTLY-EDITING/Root/@edit-id ]/@Firma
If you do not only want to show but also edit your row data, you can also copy the row to a different tree (using an “Append Node(s)” action) and modify that one.
In the subpage, the second tree is modified. If editing should be cancelled, you simply throw it away; in case of saving, you can write back the data to the original row after closing the subpage.
Hope this helps.
Altova MobileTogether Experts