Error when updating a table adapter in Visual Basic
'Open connection
Using Conn as new OleDbConnection("connection string")

  'This is the command that will update your table in the database
  Using UpdateCmd = Conn.CreateCommand()

    UpdateCmd.CommandText = "update yourtable set col1 = ?, col2 = ?"

    'Create a parameter to pass in the value of the "col1" column on "yourtable"
    Dim ColOneParam = UpdateCmd.Parameters.Add("@Col1", OleDbType.Integer)
    ColOneParam.SourceColumn = "Name of column in DataTable which corresponds to col1"

    'Create a parameter to pass in the value of the "col2" column on "yourtable"
    Dim ColTwoParam = UpdateCmd.Parameters.Add("@Col2", OleDbType.Integer)
    ColTwoParam.SourceColumn = "Name of column in DataTable which corresponds to col2"

    'Data adapter which will perform the specified update command for each
    'newly inserted row
    Using Adapter As New OleDbDataAdapter

      'Set the update command on the adapter, if you omit this line you'll
      'encounter the original error you mentioned
      Adapter.UpdateCommand = UpdateCmd

      'This is the data table containing the rows you wish to update
      Dim NewRows As New DataTable("SomeTable")

      'For each modified row in NewRows, update it in the database
      Adapter.Update(NewRows)

    End Using

  End Using

End Using