How to link two dataset in one band

I have two databases in project: ‘main’ and ‘secondary’.
Some of data for report located in main database, some data in secondary (legacy database).

I cant create SQL or JPQL query over two datastores, but I need to join datasets on some field.
In documentation there is field “Link field”. I want to use this feature, but there is no any info how to use it.
Is any info how to join two or more datasets without groovy?


The Link field is used to merge data from multiple datasets inside one band. It can be used when the whole data for the report row could not be received by a single query or a Groovy script.

You can find the sample in a and “[XLSX] Cross-tab report on sales” report. See band “sales”.

Subbotin Andrey