Using Draw.io's MacOS Desktop release,'Database 3' is a Software diagram option:
A table representation in it looks like this:
My question is, how can I add a data type to a field in a column, and not just tag it to the name? It doesn't appear to be possible, at first, on the right side-menu, nor on the initial double-click on the representation.
Upon the initial double click on the representation, single left-clicking to the right of the second column brings up the Table menu. The second button Insert Column Right allows for this:
Upon inserting it, clicking the right-arrow key positions the cursor for entry of the type: