Multiple Tables in SQLDataSource

[suganya]

Hi

I have a GridView in my Page. I have to bind multiple tables into the GridView using SQLDataSource. For that I have given the coding as

<asp:GridView ID="Search_GridView" runat="server" Style="z-index: 100; left: 2px; position: absolute;
            top: 270px" AutoGenerateColumns="False" OnSelectedIndexChanged="Search_GridView_SelectedIndexChanged" CellPadding="20" Width="720px" AllowPaging="True" OnPageIndexChanging="Search_GridView_PageIndexChanging" DataSourceID="SqlDataSource1">
            
             <Columns>
                 <asp:hyperlinkfield headertext="Doctors Name"
      datatextfield="DoctorsName"
      datanavigateurlfields="DoctorsName" 
      datanavigateurlformatstring="Logging.aspx?DoctorsName={0}" />
                     
 
                         <asp:BoundField DataField="Address" HeaderText="Address" SortExpression="Address" />
                         <asp:BoundField DataField="Phone" HeaderText="Phone" SortExpression="Phone" />
                          <asp:BoundField DataField="PrimaryTitle" HeaderText="PrimaryTitle" SortExpression="PrimaryTitle" />
                 <asp:HyperLinkField Text="Fix an Appointment" HeaderText="Appointment Fixing" NavigateUrl="~/Appointment.aspx"/>
                          
                           
                         
                         
                         
                         
                    </Columns>
            
            
           
            <HeaderStyle BackColor="InactiveCaption" BorderWidth="0px" />
            <AlternatingRowStyle BackColor="Silver" />
            
            
            
            
        </asp:GridView>
            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:Hello_DrConnectionString3 %>"
               SelectCommand="SELECT DoctorMaster.[FirstName]+''+DoctorMaster.[MiddleName]+''+DoctorMaster.[LastName] as DoctorsName,DrClinicDetails.[Address],DoctorMaster.[Telephone]+','+DoctorMaster.[Mobile]as Phone,PrimaryTitle.PrimaryTitle FROM [DoctorMaster],[DrClinicDetails],[PrimaryTitle],[Specialty] WHERE ((DoctorMaster.[FirstName] LIKE '%' + @FirstName + '%') OR (Specialty.[Specialty]=@Specialty) OR (DoctorMaster.[City] = @City)) AND DoctorMaster.[SPID]=Specialty.[SPID] AND PrimaryTitle.[PTID]=DoctorMaster.[PrimaryTitleID]">
                <SelectParameters>
                    <asp:SessionParameter DefaultValue="Name" Name="FirstName" SessionField="Name" Type="String" />
                    <asp:SessionParameter DefaultValue="Location" Name="City" SessionField="Location"
                        Type="String" />
                        <asp:SessionParameter DefaultValue="Specialty" Name="Specialty" SessionField="Specialty"
                        Type="String" />
                </SelectParameters>
            </asp:SqlDataSource>

In form load, I assigned value of session to the objects as

object obj;
        obj = (object)Session["Name"];

        object obj1;
        obj1 = (object)Session["Specialty"];

        object obj2;
        obj2 = (object)Session["Location"];

but once I run GridView is not getting displayed