Question

Why my set of codes didn’t update in DataSet? Then it goes to Error. Please anyone check this code and point me out where I am missing. Thanks in advance!

Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click

    Dim conxMain As New SqlConnection("Data Source=SERVER;Initial Catalog=DBTest;Persist Security Info=True;User ID=username;Password=pwds")

    Dim dadPurchaseInfo As New SqlDataAdapter
    Dim dsPurchaseInfo As New DataSet1
    Try
        Dim dRow As DataRow

        conxMain.Open()

        Dim cmdSelectCommand As SqlCommand = New SqlCommand("SELECT * FROM Stock", conxMain)
        cmdSelectCommand.CommandTimeout = 30

        dadPurchaseInfo.SelectCommand = cmdSelectCommand
        Dim builder As SqlCommandBuilder = New SqlCommandBuilder(dadPurchaseInfo)

        dadPurchaseInfo.Fill(dsPurchaseInfo, "Stock")


        For Each dRow In dsPurchaseInfo.Tables("Stock").Rows
            If CInt(dRow.Item("StockID").ToString()) = 2 Then
                dRow.Item("StockCode") = "Re-Fashion[G]"
            End If

        Next
        dadPurchaseInfo.Update(dsPurchaseInfo, "Stock")

    Catch ex As Exception
        MsgBox("Error : ")
    Finally
        If dadPurchaseInfo IsNot Nothing Then
            dadPurchaseInfo.Dispose()
        End If

        If dsPurchaseInfo IsNot Nothing Then
            dsPurchaseInfo.Dispose()
        End If

        If conxMain IsNot Nothing Then
            conxMain.Close()
            conxMain.Dispose()
        End If
    End Try
End Sub

Answer 1

Does your condition in the loop get executed (set a break point!)? Where is the error thrown? What error?

Also, why does it use ToString at all? This seems redundant.

If CInt(dRow.Item("StockID")) = 2 Then

Should be enough.

Finally, you’re performing redundant cleanup:

If conxMain IsNot Nothing Then
    conxMain.Close()
    conxMain.Dispose()
End If

Dispose implies Close – no need to perform both operations:

Close and Dispose are functionally equivalent.

[Source: MSDN]