Modifying Data in a Table
The DataRow class provides three methods for suspending, reactivating the state of the row while editing.
They are,
(1)BeginEdit
(2)EndEdit
(3)CancelEdit
Eg.,
Dim dr as DataRow = dt.Rows(2)
dr.BeginEdit()
dr(0)="hi"
dr(1)="22"
dr.EndEdit()
DataRowVersion
It is used when retrieving the value found in a datarow by using Item property.Four types,
(1)Current
(2)Default
(3)Original
(4)Proposed
E.g.,
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim dr As DataRow
dr = dtTable.Rows(1)
'Represents the Original value
lblOriginal.Text = "CTCID is" & dr(0, DataRowVersion.Original) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Original) & "." & "Amount is " & dr(2, DataRowVersion.Original)
'Begin to edit the row
dr.BeginEdit()
dr(0) = "2"
dr(1) = "4444"
dr(2) = "8889"
' Values are changed into 2,4444,8889(Proposed value)
lblProposed.Text = "CTCID is" & dr(0, DataRowVersion.Proposed) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Proposed) & "." & "Amount is " & dr(2, DataRowVersion.Proposed)
'Values are not changed, old original values still exists (Current Value)
lblCurrent1.Text = "CTCID is" & dr(0, DataRowVersion.Current) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Current) & "." & "Amount is " & dr(2, DataRowVersion.Current)
' Values are changed into 2,4444,8889(Default value)
lblDefault.Text = "CTCID is" & dr(0, DataRowVersion.Default) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Default) & "." & "Amount is " & dr(2, DataRowVersion.Default)
'Ending the edition of a row.
dr.EndEdit()
'Values are changed into 2,4444,8889(Current value)
lblCurrent.Text = "CTCID is" & dr(0, DataRowVersion.Current) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Current) & "." & "Amount is " & dr(2, DataRowVersion.Current)
'Values are not changed, old original values still exists (Original Value)
lblOriginal.Text = "CTCID is" & dr(0, DataRowVersion.Original) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Original) & "." & "Amount is " & dr(2, DataRowVersion.Original)
'Make changes into the datatable
dtTable.AcceptChanges()
'Now Values are changed, old original values not exists (Original Value)
lblOriginal.Text = "CTCID is" & dr(0, DataRowVersion.Original) & "." _
& "Emp_Id is" & dr(1, DataRowVersion.Original) & "." & "Amount is " & dr(2, DataRowVersion.Original)
End Sub
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