Explain the DataAdapter.Update() and DataSetAcceptChanges() methods.

Answer:

The DataAdapter.Update() method calls any of the DML statements, such as the UPDATE, INSERT, or DELETE statements, as the case may be to update, insert, or delete a row in a DataSet.

Example:

Dim NumberOfRowsUpdated As Integer 

NumberOfRowsUpdated = MyDataAdapter.Update(MyDataSet, "MyCustomer")

The DataSet.Acceptchanges() method reflects all the changes made to the row since the last time the AcceptChanges() method was called.

Example:

Private Sub AcceptChanges()

   Dim myDataSet As DataSet

   myDataSet = new DataSet()



   ' Not shown: methods to fill the DataSet with data.

   Dim t As DataTable



   t = myDataSet.Tables("Suppliers")



   ' Add a DataRow to a table.

   Dim myRow As DataRow

   myRow = t.NewRow()

   myRow("CompanyID") = "NWTRADECO"

   myRow("CompanyName") = "NortWest Trade Company"



   ' Add the row.

   t.Rows.Add( myRow )



   ' Calling AcceptChanges on the DataSet causes AcceptChanges to be

   ' called on all subordinate objects.

   myDataSet.AcceptChanges()

End Sub