Dropdown Box Inside Gridview Update Feature ASP.NET

So I have a gridview in my webpage, At the moment the table returns values from an SQL table.

Inside my table I have 'Allowed Editing/Updates' which is updating values in my SQL table from the gridview in the webpage, this functionality works fine, my only problem is... In one of the columns on the gridview I would like to have the option to Select from a drop down box (as oppose to typing in a text box like the other columns),

The drop down box would be linked to list that I have in SQL, I have tried all sorts of techniques and have searched endlessly Online to try and do this, yet I have no luck,

I was was wondering if I could get some assistance with this....

Thankyou in advance. Here is my aspx code for my gridview at the moment:

<asp:GridView ID="GridView2" runat="server" DataKeyNames="ID" AutoGenerateColumns="False" border="1" DataSourceID="SqlDataSource3" style="font-size: 0.9em; margin-left: 2%;" Width="85%">
                                    <Columns>
                                        <asp:BoundField DataField="contactName" HeaderText="contactName" SortExpression="contactName">
                                        </asp:BoundField>
                                        <asp:BoundField DataField="contactEmail" HeaderText="contactEmail" SortExpression="contactEmail">
                                        </asp:BoundField>
                                        <asp:BoundField DataField="Telephone" HeaderText="Telephone" SortExpression="Telephone">
                                        </asp:BoundField>
                                        <asp:BoundField DataField="jobRole" HeaderText="jobRole" SortExpression="jobRole">
                                        </asp:BoundField>

                                     <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
                                    </Columns>
                                </asp:GridView>
                                <br />
                                <asp:SqlDataSource ID="SqlDataSource3" 
runat="server" ConnectionString="<%$ ConnectionStrings:saleConnectionString %>" 
DeleteCommand="Delete from IMContactEmails where ID = @ID" 
SelectCommand="SELECT  contactName, contactEmail, Telephone, jobRole, ID FROM 
IMContactEmails WHERE 

(ProjectNo = @PID)" UpdateCommand="Update IMContactEmails Set 
contactName=@contactName,contactEmail=CASE WHEN 

@contactEmail IS NULL THEN contactEmail Else @contactEmail END,Telephone=CASE
WHEN 

@Telephone IS NULL THEN Telephone ELSE @Telephone END,jobRole=CASE WHEN 
@jobRole IS NULL THEN jobRole ELSE @jobRole END where ID=@ID">
                                    <DeleteParameters>
                                        <asp:Parameter Name="ID" Type="String" />
                                    </DeleteParameters>
                                    <SelectParameters>
                                        <asp:ControlParameter 
ControlID="PIDvalTextBox" Name="PID" PropertyName="Text" />
                                    </SelectParameters>
                                    <UpdateParameters>
                                        <asp:Parameter Name="contactName" />
                                        <asp:Parameter Name="contactEmail" />
                                        <asp:Parameter Name="Telephone" />
                                        <asp:Parameter Name="jobRole" />
                                        <asp:Parameter Name="ID" />
                                    </UpdateParameters>
                                </asp:SqlDataSource>

UPDATE:

Here is the code inside my columns with the TemplateField:

<asp:GridView ID="GridView2" runat="server" DataKeyNames="ID" AutoGenerateColumns="False" border="1" DataSourceID="SqlDataSource3" style="font-size: 0.9em; margin-left: 2%;" Width="85%">
    <Columns>
        <asp:BoundField DataField="contactName" HeaderText="contactName" SortExpression="contactName">
        </asp:BoundField>
        <asp:BoundField DataField="contactEmail" HeaderText="contactEmail" SortExpression="contactEmail">
        </asp:BoundField>
        <asp:BoundField DataField="Telephone" HeaderText="Telephone" SortExpression="Telephone">
        </asp:BoundField>
        <asp:TemplateField HeaderText="jobRole">
            <EditItemTemplate>
                <asp:DropDownList ID="DDLjobRole" runat="server" 
                     DataSourceID="SqlDataSource1" 
                     DataTextField="jobRole" DataValueField="jobRole" 
                     SelectedValue='<%# Bind("jobRole")%>'>
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>
        <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
    </Columns>
</asp:GridView>

Solution

Put a TemplateField in your Columns and add a dropdown list over there.

<asp:TemplateField HeaderText="Name">
    <EditItemTemplate>
        <asp:DropDownList ID="DropDownList1" runat="server" 
             DataSourceID="SqlDataSource1"               
             DataTextField="Name" DataValueField="Name" 
             SelectedValue='<%# Bind("Name") %>'>
         </asp:DropDownList>
     </EditItemTemplate>

     <ItemTemplate>
         <asp:Label id="Label1" runat="server" Text=''<%# Bind("Name") %>''
     </ItemTemplate>
</asp:TemplateField>

Add a sql data source and write the query to bind your drop down list something as below:

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="Your connection string" 
        SelectCommand="SELECT Name FROM dbo.Table"></asp:SqlDataSource>

Try it. Hope it helps.