The "Import Database" function, in the Tools menu, is intended to import data that is in Transana XML format. Such files are created by exporting data from Transana 2.0 using the "Export Database" function or by using the Data Exporter to extract data from Transana 1.22 - 1.24.
At this time, you can import data only into a new or empty database. The system does not support combining databases by importing several Transana XML files into the same database.