This example demonstrate you how can you use rad grid with datasources

Radgrid html code

 telerik:RadGrid ID="RadGrid1" runat="server" AutoGenerateColumns="False" Width="750px"
            AllowAutomaticDeletes="True" AllowAutomaticInserts="True" AllowAutomaticUpdates="True"
                                        GridLines="None" DataSourceID="SqlTransmital"
                                AllowSorting="True" Skin="Web20"
            ClientDataKeyNames="TransID" EditMode="InPlace" DataMember="DefaultView" >
                                MasterTableView AutoGenerateColumns="False" DataKeyNames="TransID" CommandItemDisplay="Top" AllowAutomaticDeletes="true" AllowAutomaticInserts="true" AllowAutomaticUpdates="true">                               
                                  Columns>
                                      telerik:grideditcommandcolumn ButtonType="ImageButton">
                                      /telerik:GridEditCommandColumn>
                                     
                                       telerik:gridboundcolumn DataField="TransID" HeaderText="TransID"
                                          Visible="false" ReadOnly="True"
                                            UniqueName="TransID">
                                        /telerik:GridBoundColumn>
                                       
                                       
                                 telerik:gridtemplatecolumn UniqueName="ReasonforIssueID"
                                          HeaderText="Reason for Issue">
                                 ItemTemplate>                                
                                 asp:Literal ID="ltrREason" runat="server"  Text ='%#Eval("Reason for Issue") %>' >/asp:Literal>
                                         
                                 /ItemTemplate>
                                 EditItemTemplate>
                                
                                 telerik:radcombobox runat="server"
                                             ID="ddlReasonEdit"
                                             DataTextField="Reason_for_Issue"
                                             DataValueField="ReasonforIssueID"
                                             HighlightTemplatedItems="true"
                                             Height="190px"
                                             Width="200px"
                                             DropDownWidth="200px"
                                             EnableItemCaching="True"
                                             EnableLoadOnDemand="True"
                                             emptymessage="Please select one..."
                                             allowcustomtext="True"
                                                DataSourceID="sqlReason"
                                                SelectedValue='%#Bind("ReasonforIssueID") %>'>/telerik:RadComboBox>
                                               
                                  asp:RequiredFieldValidator ID="RequiredFieldValidator3" ControlToValidate="ddlReasonEdit" runat="server" ErrorMessage="*">/asp:RequiredFieldValidator>
                                                
                                               
                                
                                 /EditItemTemplate>
                                        /telerik:GridTemplateColumn>
                                 
                                        telerik:gridboundcolumn DataField="OurDocRev" HeaderText="Cam Doc Rev"
                                            UniqueName="OurDocRev">
                                        /telerik:GridBoundColumn>
                                       
                                                                              
                                        
                                         telerik:gridtemplatecolumn UniqueName="OurTransDate"
                                          HeaderText="Cam to Client Trans Date">
                                         ItemTemplate>
                                        
                                         asp:Literal ID="TDate" runat="server"     Text ='%#Bind("OurTransDateF") %>' >/asp:Literal>
                                        
                                           
                                        
                                         /ItemTemplate>
                                        
                                         EditItemTemplate>
                                             telerik:raddatepicker ID="RadOurTransDateEdit" runat="server"
                                                 DbSelectedDate='%#Bind("OurTransDate") %>' Width="100px"
                                                 DateInput-DateFormat="dd/MM/yyyy"  >
                                             /telerik:RadDatePicker>
                                        
                                         /EditItemTemplate>
                                         /telerik:GridTemplateColumn>                               
                                       
                                       
                                         telerik:GridBoundColumn DataField="OurTransNo" HeaderText="Cam to Client Trans No"
                                          UniqueName="OurTransNo">
                                      /telerik:GridBoundColumn>
                                       
                                       
                                         telerik:gridboundcolumn DataField="ClientDocRev" HeaderText="Client Doc Rev"
                                            UniqueName="ClientDocRev">
                                        /telerik:GridBoundColumn>
                                       
                                         
                                       
                                       
                                        telerik:gridtemplatecolumn UniqueName="ClientTransRetDate"
                                          HeaderText="Client Return Trans Date">
                                         ItemTemplate>
                                             asp:Literal ID="TCDate" runat="server"     Text ='%#Bind("ClientTransRetDateF") %>' >/asp:Literal>

                                           
                                        
                                         /ItemTemplate>
                                        
                                         EditItemTemplate>
                                             telerik:raddatepicker ID="RadCRtrnDateEdit" runat="server"
                                                 DbSelectedDate='%#Bind("ClientTransRetDate") %>' Width="100px"
                                                 DateInput-DateFormat="dd/MM/yyyy">
                                             /telerik:RadDatePicker>
                                        
                                         /EditItemTemplate>
                                         /telerik:GridTemplateColumn>
                                      
                                       
                                         telerik:gridboundcolumn DataField="ClientRtrnTransNo" HeaderText="Client Return Trans No"
                                            UniqueName="ClientRtrnTransNo">
                                        /telerik:GridBoundColumn>
                                     
                                        telerik:gridtemplatecolumn UniqueName="ClientRtrnCodeID"
                                          HeaderText="Client Return Code">
                                         ItemTemplate>
                                        
                                          asp:Literal ID="ltrClientRtn" runat="server"     Text ='%#Eval("Client Rtrn Code") %>' >/asp:Literal>
                                         
                                
                                                                                        
                                 /ItemTemplate>
                                 EditItemTemplate>
                                
                                 telerik:radcombobox runat="server"
                                             ID="ddlClientReturnEdit"
                                             DataTextField="ReturnDescription"
                                             DataValueField="ClientRtrnCodeID"
                                             HighlightTemplatedItems="true"
                                             Height="190px"
                                             Width="200px"
                                             EnableItemCaching="True"
                                             EnableLoadOnDemand="True"
                         DropDownWidth="200px"
                         emptymessage="Please select one..."
                                             allowcustomtext="True"
                                             DataSourceID="sqlClientReturn"
                                             SelectedValue='%#Bind("ClientRtrnCodeID") %>'>/telerik:RadComboBox>
                    
                                
                                 /EditItemTemplate>
                                
                                 /telerik:GridTemplateColumn>
                                   telerik:gridbuttoncolumn ButtonType="ImageButton" CommandName="Delete" ConfirmText="Are you sure delete this record?"
                                        Text="Delete" UniqueName="column1">
                                    /telerik:GridButtonColumn>
                                    /Columns>
                                EditFormSettings>

             EditColumn ButtonType="ImageButton" InsertText="Insert Order" UpdateText="Update record"
                        UniqueName="EditCommandColumn1" CancelText="Cancel edit">
                    /EditColumn>


                                /EditFormSettings>
                                /MasterTableView>
                                  /telerik:RadGrid>

Datasource code here

 asp:SqlDataSource ID="SqlTransmital"
                                   
                                    ConnectionString="%$ ConnectionStrings:SiteSqlServer %>"
                                    SelectCommand="SELECT convert(varchar(10),OurTransDate,103) as OurTransDateF,convert(varchar(10),ClientTransRetDate,103) as ClientTransRetDateF, * FROM [qry_Data_Transmittal] WHERE (DocNo = @DocNo)"
                                    DeleteCommand ="Delete from [tbl_DATA_Transmittals] where TransID=@TransID"
                                   
                                    InsertCommand="insert into tbl_DATA_Transmittals ([OurDocRev],[OurTransDate],ReasonforIssueID,
                                    [ClientTransRetDate],[ClientRtrnTransNo],ClientRtrnCodeID,DocNo,ClientDocRev,[OurTransNo]) values(@OurDocRev,@OurTransDate,
                                    @ReasonforIssueID,@ClientTransRetDate ,@ClientRtrnTransNo,@ClientRtrnCodeID,@DocNo,@ClientDocRev,@OurTransNo) "
                                   
                                    UpdateCommand="update tbl_DATA_Transmittals set [OurDocRev]=@OurDocRev, [OurTransDate]=@OurTransDate,[OurTransNo]=@OurTransNo,
                                    ReasonforIssueID=@ReasonforIssueID, [ClientTransRetDate]=@ClientTransRetDate,
                                    [ClientRtrnTransNo]=@ClientRtrnTransNo,ClientRtrnCodeID=@ClientRtrnCodeID, ClientDocRev=@ClientDocRev where TransID=@TransID" runat="server">
                                                                               
                                   
                                  SelectParameters>                                                                          
                                        asp:ControlParameter ControlID="Label1" PropertyName="Text" Type="String" Name="DocNo" />
                                    /SelectParameters>
                                    DeleteParameters>
                                        asp:Parameter Name="TransID" Type="Int32" />
                                   
                                    /DeleteParameters>
                                   
                                    UpdateParameters>
                                    asp:Parameter Name="TransID" Type="Int32" />                                   
                                    asp:Parameter Name="OurDocRev" Type="String" />
                                    asp:Parameter Name="OurTransDate" Type="DateTime" />
                                    asp:Parameter Name="OurTransNo" Type="Int32" />
                                    asp:Parameter Name="ReasonforIssueID" Type="Int32" />
                                    asp:Parameter Name="ClientTransRetDate" Type="DateTime" />
                                    asp:Parameter Name="ClientRtrnTransNo" Type="Int32" />
                                    asp:Parameter Name="ClientRtrnCodeID" Type="Int32" />
                                    asp:Parameter Name="ClientDocRev" Type="String" />
                                   
                                   
                                    /UpdateParameters>
                                   
                                    InsertParameters>   
                                    asp:Parameter Name="OurDocRev" Type="String" />
                                    asp:Parameter Name="OurTransDate" Type="DateTime" /> 
                                     asp:Parameter Name="OurTransNo" Type="Int32" />                                
                                    asp:Parameter Name="ReasonforIssueID" Type="Int32" />
                                    asp:Parameter Name="ClientTransRetDate" Type="DateTime" />
                                    asp:Parameter Name="ClientRtrnTransNo" Type="Int32" />
                                    asp:Parameter Name="ClientRtrnCodeID" Type="Int32" />
                                    asp:ControlParameter ControlID="Label1" PropertyName="Text" Type="String" Name="DocNo" />
                                    asp:Parameter Name="ClientDocRev" Type="String" />
                                      
                                    /InsertParameters>

                                   
                                /asp:SqlDataSource>