Mail Merge for Microsoft Access® is without doubt the most flexible mail merge tool on the market. One of its power features is that it can assign multiple data sources to one process to play different roles. Data sources can either play the role of
In many cases 1. and 2. are the same, in which case the distinction is irrelevant (and the combo boxes in the wizard are invisible). The distinction becomes apparent when the user interface is built up from a split form interface (see screenshot at the bottom of the page). Such a split screen usually consists of a form showing an overview of the data, and a form (instance) showing the data corresponding to the current selected record in the overview. Though related, the instance form typically contains a set of fields (often the complete set) different from the overview. The overview form (should) contain only fields relevant to select records with, either using Access' Find or Filter.
Because the set of fields available differs, when you are working with a form with subforms (such as with the Demo Database frmMain, see below) you will have to be especially careful about which Access object you assign which role (iterate over or fill template from). If you select the wrong datasource, you will easily be confused by the fact that fields which you expect to find are not available in Template Designer.