ASPNet Dropdown List from 0 to quantity available - mysql

Question

I'm creating a webform for a Class assignment that essentially allows you to select a quantity from 0 to the amount available for each product. We're using AdventureWorks 2014 as our datasource.
However it only displays the maximum quantity and not from 0 to the max quantity.
I'm just stuck on what to add so it can display 0 to max quantity. Thanks.
I don't have anything in regards to the code behind, it's just the basic:
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnOrder_Click(object sender, EventArgs e)
{
}
protected void ddlQuantity_SelectedIndexChanged(object sender, EventArgs e)
{
}
}

Answer 1

You can perform binding by handling SelectedIndexChanged event from ddlProductName to fill ddlQuantity items:
ASPX
<asp:DropDownList ID="ddlProductName" runat="server" AutoPostBack="True" DataSourceID="ddlProductNameitems" DataTextField="Name" DataValueField="Name"
OnSelectedIndexChanged="ddlProductName_SelectedIndexChanged">
</asp:DropDownList>
<asp:DropDownList ID="ddlQuantity" runat="server" AutoPostBack="True" ...></asp:DropDownList>
Then use a List collection to store all numbers from 0 to maximum value set by SUM query then bind that List to DropDownList in SelectedIndexChanged event given above:
ASPX.cs (code-behind)
protected void ddlProductName_SelectedIndexChanged(object sender, EventArgs e)
{
List<string> quantities = new List<string>();
int maxQuantity = 0;
// retrieve SUM result from SqlDataSource
// if 'DataSourceSelectArguments.Empty' doesn't work, try other 'DataSourceSelectArguments' options
DataView view = QuantityChoices.Select(DataSourceSelectArguments.Empty) as DataView;
// set maximum quantity from SUM query result
if (view != null)
{
maxQuantity = int.Parse(view.Table.Rows[0]["TotalInventory"].ToString());
}
else
{
// assign maxQuantity from SqlConnection here
}
// add every quantity amount to the list...
for (int i = 0; i <= maxQuantity; i++)
{
quantities.Add(i.ToString());
}
// ... then sort from least value...
quantities.Sort();
// ... and bind the list here!
ddlQuantity.DataSource = quantities;
ddlQuantity.DataBind();
}
NB: System.Data namespace should be added to use DataView component. Note that it may necessary to remove DataSourceID, DataTextField & DataValueField from ddlQuantity to bind corresponding DropDownList with generated list of quantities.