Updating items in form view

sophia · October 30th, 2009, 02:51 PM

Thank you sir for last post. That really helped me out.
But as problems never end, I have another problem. Well not used in book but I wanna add functionality of updating products in AddProduct.aspx file.
I have used Edit Item Template with Form view and added events like
OnItemInserting = "FormView1_ItemInserting" OnItemUpdating= "FormView1_ItemUpdating"
OnItemInserted = "FormView1_ItemInserted" OnItemUpdated = "FormView1_ItemUpdated"
AddProduct.aspx page looks like

Code:

<asp:FormView ID="FormView1" runat="server" DataSourceID="odsProducts" DefaultMode="Insert" DataKeyNames = "Id" 
 OnItemInserting = "FormView1_ItemInserting" OnItemUpdating= "FormView1_ItemUpdating" 
 OnItemInserted = "FormView1_ItemInserted" OnItemUpdated = "FormView1_ItemUpdated" >
    <EditItemTemplate >
    <h1>Update The Product</h1>
      <table border="0" cellpadding="3" cellspacing="0" style="width: 100%; height: 100%">
      <tr>
        <td class="Label" valign="top">
          Title:
        </td>
        <td>
          <asp:TextBox ID="TitleTextBox" runat="server" Text='<%# Bind("Title") %>' Width="300px" />
          <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TitleTextBox" ErrorMessage="Please Enter A Title" Display="Dynamic"></asp:RequiredFieldValidator>
        </td>
      </tr>
      <tr>
        <td class="Label" valign="top">
          Description:</td>
        <td>
          <asp:TextBox ID="DescriptionTextBox" runat="server" Text='<%# Bind("Description") %>' TextMode="MultiLine" Width="300px" Height="106px" />
          <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="DescriptionTextBox" ErrorMessage="Please Enter A Description" Display="Dynamic"></asp:RequiredFieldValidator>
        </td>
      </tr>
      <tr>
        <td class="Label" valign="top">
          Category:
        </td>
        <td>
          <asp:DropDownList ID="lstCategoryId" runat="server" DataSourceID="odsProductCategories" DataTextField="Description" DataValueField="Id">
          </asp:DropDownList>
        </td>
      </tr>
      <tr>
        <td class="Label" valign="top">
          Price:
        </td>
        <td>
          <asp:TextBox ID="PriceTextBox" runat="server" Text='<%# Bind("Price") %>' Width="300px" />
          <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="PriceTextBox" ErrorMessage="Please Enter The Price" Display="Dynamic"></asp:RequiredFieldValidator><asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="PriceTextBox" ErrorMessage="Please Enter A Number Between 0 And 10000" MaximumValue="10000" MinimumValue="0" Type="Currency" Display="Dynamic"></asp:RangeValidator>
        </td>
      </tr>
      <tr>
        <td class="Label" valign="top">
          Image:</td>
        <td>
          <asp:FileUpload ID="FileUpload1" runat="server" Width="300px" />
          <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ControlToValidate="FileUpload1" Display="Dynamic" ErrorMessage="Please Select An Image First"></asp:RequiredFieldValidator></td>
      </tr>
      <tr>
        <td>
        </td>
        <td>
          &nbsp;<asp:Button ID="btnInsert" runat="server" CommandName="Insert" Text="Insert" />
          <asp:Button ID="btnCancel" runat="server" CommandName="Cancel" Text="Cancel" CausesValidation="False" OnClick="btnCancel_Click" />
        </td>
      </tr>
      </table>
      <br />
      <br />
      <br />
      &nbsp;<br />
      <br />
      &nbsp;
    </EditItemTemplate>
      
    <InsertItemTemplate>
Same implementation as in book.....
 </InsertItemTemplate>
</asp:FormView>

I have changed the corresponding object data source as

Code:

<asp:ObjectDataSource ID="odsProducts" runat="server" DataObjectTypeName="Product" InsertMethod="InsertProduct" SelectMethod="GetProduct" UpdateMethod="UpdateProduct"  TypeName="ShopManager">

Also added update method in the ShopManagerDB.vb and called it from ShopManager.vb

Code:

 Public Shared Sub UpdateProduct(ByVal theProduct As Product)
        Try
            Using myConnection As New SqlConnection(AppConfiguration.ConnectionString)

                Dim myCommand As SqlCommand = New SqlCommand("sprocProductInsertUpdateSingleItem", myConnection)
                myCommand.CommandType = CommandType.StoredProcedure

                myCommand.Parameters.Clear()
                myCommand.Parameters.AddWithValue("@title", theProduct.Title)
                myCommand.Parameters.AddWithValue("@description", theProduct.Description)
                myCommand.Parameters.AddWithValue("@price", theProduct.Price)
                myCommand.Parameters.AddWithValue("@categoryId", theProduct.CategoryId)
                myCommand.Parameters.AddWithValue("@pictureUrlSmall", theProduct.PictureUrlSmall)
                myCommand.Parameters.AddWithValue("@pictureUrlMedium", theProduct.PictureUrlMedium)
                myCommand.Parameters.AddWithValue("@pictureUrlLarge", theProduct.PictureUrlLarge)

                myConnection.Open()

                myCommand.ExecuteNonQuery()
                myConnection.Close()
            End Using
        Catch ex As Exception
            ' Pass up the error; it will be caught by the code in the Global.asax and the generic error page set up in web.config.
            Throw
        End Try
    End Sub

But rather than updating item it inserts item in the database. For this purpose I had removed

Code:

If theProduct.Id = -1 Then
          myCommand.Parameters.AddWithValue("@id", DBNull.Value)
        Else
          myCommand.Parameters.AddWithValue("@id", theProduct.Id)
        End If

And used myCommand.Parameters.Clear() to get rid off previous value but still it is not working.....
please help me in this regard.......
And yeah once again thank you for last post

Imar · October 30th, 2009, 03:33 PM

Maybe Product.Id doesn't default to -1?

Imar

sophia · October 30th, 2009, 04:14 PM

Well I have tried the update method with and without theProduct.Id = -1 as well

Code:

If theProduct.Id = -1 Then
                    myCommand.Parameters.AddWithValue("@id", DBNull.Value)
                Else
                    myCommand.Parameters.AddWithValue("@id", theProduct.Id)
                End If

But it always inserts the product instead of updating it.
Well according you what should be the procedure of updating items using form view. Maybe my approach is wrong at all.
So is there any other way of implementing update using form view.
Thank you sir.......

Imar · October 30th, 2009, 05:03 PM

What I meant was the initial value of the Id. Take a look at this:

If theProduct.Id = -1 Then

What if the default value of Id = 0, the default for an Integer? Then it always assumes an update....

Likewise, if the Id is never set when you load an item from the database using something like GetProduct, its value may always be -1 and an Insert always occurs.

Imar