Drag the tables you need from the Solution Explorer onto the LINQ Designer
Here is the code for the simple form to add a magazine to the database.
Default.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>New Magazine</h1>
<asp:Label ID="Label1" runat="server" Text="Enter Magazine Name"></asp:Label>
<asp:TextBox ID="txtMagazineName" runat="server"></asp:TextBox><br />
<asp:DropDownList ID="ddlMagazineType" runat="server">
</asp:DropDownList><br />
<asp:DropDownList ID="ddlSubscriptionType" runat="server">
</asp:DropDownList><br />
<asp:Label ID="Label2" runat="server" Text="Enter Price"></asp:Label>
<asp:TextBox ID="txtPrice" runat="server"></asp:TextBox><br />
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
</div>
</form>
</body>
</html>
Here is the code behind.
Default.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
//instantiate the data context
MagazineDataDataContext dc = new MagazineDataDataContext();
protected void Page_Load(object sender, EventArgs e)
{
//make sure it only happens on the original post of the page
if (!IsPostBack)
{
//call the methods that fill the drop down lists
FillMagazineType();
FillSubscriptionType();
}
}
protected void Button1_Click(object sender, EventArgs e)
{
//instantiate the Magazine Class. It is mapped
//to the magazine table in the database
Magazine mag = new Magazine();
//assign values to the magazine instance
mag.MagName = txtMagazineName.Text;
mag.MagType = ddlMagazineType.SelectedItem.ToString();
//mark it for insert on submit
dc.Magazines.InsertOnSubmit(mag);
MagazineDetail md = new MagazineDetail();
md.Magazine = mag; //tie it to the magazine we just made
md.SubscriptTypeID = int.Parse(ddlSubscriptionType.SelectedValue.ToString());
md.SubscriptionPrice = decimal.Parse(txtPrice.Text);
dc.MagazineDetails.InsertOnSubmit(md);
dc.SubmitChanges(); //submit the rows to the database
}
private void FillMagazineType()
{
//a linq query to get the magazine type
//it uses Distinct because in the magazines table
//several different magazines have the same types
//distinct keeps it from repeating
var mtype = (from t in dc.Magazines
orderby t.MagType
select new { t.MagType }).Distinct();
//bind the result of the query to the control
ddlMagazineType.DataSource = mtype.ToList();
ddlMagazineType.DataTextField = "MagType";
ddlMagazineType.DataBind();
}
private void FillSubscriptionType()
{
//LINQ query gets the fields from SubscriptionType
var subType = from s in dc.SubscriptionTypes
orderby s.SubscriptTypeName
select new { s.SubscriptTypeID, s.SubscriptTypeName };
ddlSubscriptionType.DataSource = subType.ToList();
ddlSubscriptionType.DataTextField = "SubscriptTypeName";
ddlSubscriptionType.DataValueField = "SubscriptTypeID";
ddlSubscriptionType.DataBind();
}
}
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