My project working well, but there no relationship between the tables of database because each table working alone I want make relationship between them even that order to change some names of the tables and I want this relationship to work in the project well For example: -From this table -To this Online Car Sales/EWAPP/AdminAddNewItem.aspx <%@ Page Language="C#" MasterPageFile="~/AdminMasterPage.master" MaintainScrollPositionOnPostback="true" AutoEventWireup="true" CodeFile="AdminAddNewItem.aspx.cs" Inherits="AdminPage" Title="OurShopping - Online Shopping Store" %> <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"> <style type="text/css"> .style9 { text-decoration: underline; } </style> </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"> <hr> <p> <span __designer:mapid="16c" class="style9">Adding New Item:</span> <br __designer:mapid="d3" /> <br __designer:mapid="d4" /> <br __designer:mapid="d5" /> Product's Name: </p> <p> <asp:TextBox ID="txtProductName" runat="server"></asp:TextBox> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtProductName" ErrorMessage="Product's Name is Requierd">*</asp:RequiredFieldValidator> <br __designer:mapid="169" /> <br __designer:mapid="16a" /> Product's Short Description:</p> <p> <asp:TextBox ID="txtShortDescription" runat="server" Height="62px" TextMode="MultiLine" Width="326px"></asp:TextBox> <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txtShortDescription" ErrorMessage="Description is Reqiuerd">*</asp:RequiredFieldValidator> </p> <p> <br __designer:mapid="d7" /> <br __designer:mapid="d8" /> Product's Description: </p> <p> <asp:TextBox ID="txtProductDescription" runat="server" Height="156px" TextMode="MultiLine" Width="375px"></asp:TextBox> <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="txtProductDescription" ErrorMessage="Description is Requierd">*</asp:RequiredFieldValidator> <br __designer:mapid="da" /> <br __designer:mapid="db" /> Make: <asp:DropDownList ID="dropCatInsert" runat="server" DataSourceID="SqlDataSource2" DataTextField="Category" DataValueField="Category"> </asp:DropDownList> <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ Connec.