In my post on Formatting Concatenated Datasources I mentioned the better way to do thangs was to use a data template to connect and execute queries on each databases and bring back a grouped/formatted data set. So rather than the concatenated data set, thus we use a data template to generate a hierarchical data set thus: Remember, this is executing a query on SQLServer (or other db) to fetch the VENDOR data and executing another ‘child’ query on Oracle (or another db) to fetch the vendor’s PO data. This will allow you to simplify the layout template removing the need for the variables and the XPATH expression
Excerpt from:
Multi Database Data Templates
