Question

This may seem very trivial, I used to know how to do this at one time but for some reason I can’t seem to get my head around it this time:

I have two tables: Hotel and HotelRooms
The Hotel table has HotelID and other hotel details and the HotelID is found in HotelRooms with different roomtypes, each roomtype has a description.
One Hotel can have many rooms types.

I have a DropDownList that contains HotelID and RoomIDs. HotelID comes from a session variable. HotelID is the value for the DropDownList; but the list displaysRoomType.
WhenRoomtypesare selected I want to display aGridView` with the hotel room details like description, price etc….

I can’t do this because the value for my DropDownList is HotelID which is mapped to the Session ID. How do I get the HotelRoom details from the selected value of the DropDownList, please?

Update:

Code for Gridview:

        string intResortID = Request.QueryString("intResortID ")
        string strRoomType = DropDownList2.SelectedValue;
        string connStr = ConfigurationManager.ConnectionStrings["bdsConnectionString"].ConnectionString;
        SqlConnection Con = new SqlConnection(connStr);
        SqlDataAdapter sdr = new SqlDataAdapter("SELECT TOP (100) PERCENT tblAvail.dtm, tblResortsRooms.strRoomType, tblResortsRooms.strDescription, tblAvail.intQty, tblAvail.curPrice, tblAvail.intResortID, tblResortsRooms.intWSCode FROM tblAvailable INNER JOIN tblResortsRooms ON tblAvail.intResortID = tblResortsRooms.intResortID AND tblAvail.strRoomType = tblResortsRooms.strRoomType WHERE (tblResortsRooms.curRecRate > 0) AND (tblAvail.intResortID = @intResortID) AND (tblAvail.strRoomType = @strRoomType) AND (tblAvailable.dtm >= { fn CURDATE() }) ORDER BY tblResortsRooms.strRoomType",Con);
        SqlParameter ResID = new SqlParameter("@intResortID", intResortID);
        SqlParameter RoomType = new SqlParameter("@strRoomType", strRoomType);
        sdr.SelectCommand.Parameters.Add(ResID);
        sdr.SelectCommand.Parameters.Add(RoomType);

      <asp:DropDownList ID="DropDownList2" runat="server" 
        DataSourceID="SqlDataSource2" DataTextField="strRoomType" 
        DataValueField="intResortID" 
        onselectedindexchanged="DropDownList2_SelectedIndexChanged" 
        AutoPostBack="True">
    </asp:DropDownList>
    <asp:SqlDataSource ID="SqlDataSource2" runat="server" 
       SelectCommand="SELECT [intResortID], [strRoomType] FROM [tblResortsRooms] WHERE ([intResortID] = @intResortID)">
        <SelectParameters>
            <asp:ControlParameter ControlID="DropDownList1" Name="intResortID" 
                PropertyName="SelectedValue" Type="Int32" />
        </SelectParameters>
    </asp:SqlDataSource>

Answer 1

‘DropDownList1.SelectedValue’ should give you the value for @intResortID.
‘DropDownList2.SelectedValue’ should give you the value for @strRoomType.

DropDownList2_SelectedIndexChanged should run the query by filling something (like a DataTable).
The filled DataTable should be bound to your GridView.

Try something like the following in your DropDownList2_SelectedIndexChanged method:

string intResortID = Request.QueryString("intResortID ");
string strRoomType = DropDownList2.SelectedValue;
string connStr = ConfigurationManager.ConnectionStrings["bdsConnectionString"].ConnectionString;
SqlConnection Con = new SqlConnection(connStr);
SqlDataAdapter sdr = new SqlDataAdapter("SELECT TOP (100) PERCENT tblAvail.dtm, tblResortsRooms.strRoomType, tblResortsRooms.strDescription, tblAvail.intQty, tblAvail.curPrice, tblAvail.intResortID, tblResortsRooms.intWSCode FROM tblAvailable INNER JOIN tblResortsRooms ON tblAvail.intResortID = tblResortsRooms.intResortID AND tblAvail.strRoomType = tblResortsRooms.strRoomType WHERE (tblResortsRooms.curRecRate > 0) AND (tblAvail.intResortID = @intResortID) AND (tblAvail.strRoomType = @strRoomType) AND (tblAvailable.dtm >= { fn CURDATE() }) ORDER BY tblResortsRooms.strRoomType", Con);
SqlParameter ResID = new SqlParameter("@intResortID", intResortID);
SqlParameter RoomType = new SqlParameter("@strRoomType", strRoomType);
sdr.SelectCommand.Parameters.Add(ResID);
sdr.SelectCommand.Parameters.Add(RoomType);
DataTable results = new DataTable();

sdr.Fill(results);

resultsGridView.DataSource = results;   //Assuming resultsGridView is the name of the GridView on your ASPX page.
resultsGridView.DataBind();