How to join data sets
In Data Explorer, right-click Data Sets, and choose New Joint Data Set.
Select the first data set for the joint data set from the drop-down list at the left of New Joint Data Set. The columns of the first data set appear in the panel below your selection.
Select the second data set for the joint data set from the drop-down list at the right of New Joint Data Set. The columns of the second data set appear.
Select the columns to join. Select one column from the first data set, and one column from the second data set.
Typically, you select the columns that are common to both data sets. BIRT Report Designer does not prevent you from selecting two unrelated columns. Doing so, however, typically does not provide the results you want.
Figure 3‑6 shows an example of a joint data set definition.
Joint data set definition
Select a join type, then choose Finish.
On Edit Data Set, choose Preview Results to see the rows returned by the joint data set.