To the best of my knowledge the only way is to call Clear() on the DataSet and then Fill() on each DataAdapter. If you want to undo any changes to the current data you call RejectChanges() on the DataSet.
i have a kind of main form
when that form opens, a other form is automaticly opened with borderstyle none, so without the menubar and stuff,
in the second form a couple of textboxes should be filled in, and some things have to be chosen from comboboxes. when the thing you want is not in the combobox, you can press the "new" button next to the combobox, which opens a new form (also with borderstyle none). in that last form you then can save a new thing for example a new presentation, or a group, ... when i press the save button, the new thing is saved to the database, after it is saved, the form closes and we end up back in the main form, (it should actually be, that we end up back at the previous form, but that's a problem for later) but when i show the form with the textboxes and combo's again, the thing we added to the database isn't shown in the combobox.
Sorry for the delay in replying. If you are still having an issue, I would ask whether you're passing this DataSet from Form to Form by reference. The DataSet is disconnected from the data source, so unless you are updating the data source in the child Forms using the same DataSet as you use in the parent Form, your parent Form won't know about the changes that have been made. If you pass the DataSet from the parent Form to the child Forms as a public property or a constructor argument by reference, all changes made to the data by the children will be reflected in the parent.