How Does Datanamic DataDiff Select the Comparison Key When Adding a Table To the Project, and Why It Is Not Specified for Some of the Tables?

By default, Datanamic DataDiff uses the primary key constraint as the comparison key if the constraint exists in both databases. When there is no primary key, the program selects a unique index or constraint it comes across. If still no suitable comparison key is found then you must define a comparison key in the Edit columns settings dialog.