Im building an application that connects to a SQL Server. I have a datagrid on the form and when I make a change to the data and try to clikc the save command on the form, I get the following error:

InvalidOperationException was unhandled


code:

Public Class Form1

    Private Sub MainDataBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MainDataBindingNavigatorSaveItem.Click
        Me.Validate()
        Me.MainDataBindingSource.EndEdit()
        Me.MainDataTableAdapter.Update(Me.HRPCTSDataSet.Ma inData)

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'HRPCTSDataSet.MainData' table. You can move, or remove it, as needed.
        Me.MainDataTableAdapter.Fill(Me.HRPCTSDataSet.Main Data)

    End Sub
End Class

I feel real silly. I didn't define my primary key in my table on SQL Server.