如何将DetailsView中的下拉列表绑定到其他表

Question

I'm new to asp.net and I need some help, please. I'm using c# and sql.

What I want to do is the following: I have a details view where I can use it to add Employees and save it to my database in Employee table. Within the details view, I'v created a template field for dept_id (this field is a foreign key). I want to make it as a drop down list where you can choose the department name (which is in the Department table) instead of entering the department id. I'm very stick in this. Any help will be appreciated.

This is the .aspx

    <asp:DetailsView ID="DetailsView2" runat="server" AutoGenerateRows="False" 
                CellPadding="4" DataKeyNames="Emp_Id" DataSourceID="SqlDataSource3" 
                DefaultMode="Insert" ForeColor="#333333" GridLines="None" Height="50px" 
                Width="149px">
                <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                <CommandRowStyle BackColor="#E2DED6" Font-Bold="True" />
                <EditRowStyle BackColor="#999999" />
                <FieldHeaderStyle BackColor="#E9ECF1" Font-Bold="True" />
                <Fields>
                    <asp:BoundField DataField="Emp_Id" HeaderText="Emp_Id" InsertVisible="False" 
                        ReadOnly="True" SortExpression="Emp_Id" />
                    <asp:BoundField DataField="FirstName" HeaderText="FirstName" 
                        SortExpression="FirstName" />
                    <asp:BoundField DataField="LastName" HeaderText="LastName" 
                        SortExpression="LastName" />
                    <asp:BoundField DataField="EndUser" HeaderText="EndUser" 
                        SortExpression="EndUser" />



                    <asp:TemplateField HeaderText="Dept_id" SortExpression="Dept_id">
                        <EditItemTemplate>
                            <asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="ddlSqlDataSource"
                            DataTextField="dept_name" DataValueField="dept_id" SelectedValue='<%# Bind("dept_id") %>'>
                            </asp:DropDownList>
                        </EditItemTemplate>


                        <InsertItemTemplate>
                            <asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="ddlSqlDataSource"
                            DataTextField="dept_name" DataValueField="dept_id" SelectedValue='<%# Bind("dept_id") %>'>
                            </asp:DropDownList>
                        </InsertItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label5" runat="server" Text='<%# Bind("Dept_id") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>



                    <asp:BoundField DataField="Email" HeaderText="Email" SortExpression="Email" />
                    <asp:BoundField DataField="title" HeaderText="title" SortExpression="title" />




                    <asp:TemplateField HeaderText="JoinDate" SortExpression="JoinDate">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("JoinDate") %>' TextMode="Date"></asp:TextBox>
                        </EditItemTemplate>
                        <InsertItemTemplate>
                            <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("JoinDate") %>' TextMode="Date"></asp:TextBox>
                        </InsertItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label2" runat="server" Text='<%# Bind("JoinDate") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:CommandField ButtonType="Button" ShowInsertButton="True" />

                </Fields>
                <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
            </asp:DetailsView>

I don't know what should I add exactly to the (ddlSqlDataSource)

<asp:SqlDataSource ID="ddlSqlDataSource" runat="server" 
                ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
                SelectCommand="SELECT [dept_name] FROM [Department]">
            </asp:SqlDataSource>

Answer 1

I have Solved the problem

.aspx

<asp:TemplateField HeaderText="Dept_id" SortExpression="Dept_id">
                      <ItemTemplate>
                      <%#Eval("dept_id") %>
                      </ItemTemplate>

                       <InsertItemTemplate>
                           <asp:DropDownList ID="ddlDept" runat="server" DataSourceID="ddlSqlDataSource"
                           DataTextField="dept_name" DataValueField="dept_id" SelectedValue='<%# Bind("Dept_id") %>'>
                           </asp:DropDownList>
                            <asp:SqlDataSource ID="ddlSqlDataSource" runat="server"
              ConnectionString="<%$ ConnectionStrings:ConnectionString %>"

               SelectCommand="SELECT dept_id, dept_name FROM Department ">

           </asp:SqlDataSource>
                       </InsertItemTemplate>
                       <ItemTemplate>
                           <asp:Label ID="Label5" runat="server" Text='<%# Bind("Dept_id") %>'></asp:Label>
                       </ItemTemplate>
                   </asp:TemplateField>

Code behind:

protected void DetailsView2_DataBound(object sender, EventArgs e)
    {
        DropDownList ddlDept = (DropDownList)DetailsView2.FindControl("ddlDept");

        ddlDept.Items.Insert(0, new ListItem("Select department"));

    }

Answer 2

I solved my similar problem in the databound handler in code behind:

protected void OrgsDetailView1_DataBound(object sender, EventArgs e)
{
    if (OrgsDetailsView1.CurrentMode == DetailsViewMode.Edit)
    {
        var drpCategory = OrgsDetailsView1.FindControl("drpCategory") as DropDownList;
        if (drpCategory != null) 
        {
            //drops to here when in edit mode and dropdownList is available.
            //next 3 lines just get the dataTable (catsdt)
            var cats = new Categories();  //class that gets dataTable
            var prm = new ParmsClass();  //parameter for stored procedure
            var catsdt = cats.GetAll(prm);  //gets the dataTable

            // load the dropdownlist
            drpCategory.DataSource = catsdt;
            drpCategory.DataTextField = "name";
            drpCategory.DataValueField = "Id";
            drpCategory.DataBind();
        }