Setting up a primary Key on C# Window Form App

Question

Hi Experts

I would like to set a primary on my form in C# because at the moment whenever I try to save data an error pops up as follows:

(1) StaffID is not Nullable , please check again?????

is there a way to sort out this????????

The data is properly binded to the data tables in SQL server 2016 using the wizard and is saved by using the built in Navigator binding source with a small modification below:

this.Validate();

this.customersBindingSource.EndEdit();

this.ordersBindingSource.EndEdit();

this.tableAdapterManager.UpdateAll(this.DataSet1);

Regards

Chris