Introduction
Today, in this article you will see the most useful operations "sum" and "except" in LINQ.
Sum Operation Using LINQ
Question: What is sum operation?
In simple terms "It is used to project the result set with an addition operation for the requested data".
Step 1: Create a new "ASP.NET Web Application", as in:
![Linq-sum-application.jpg]()
Step 2: The complete code of WebForm1.aspx looks like this:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="LINQ_Sum_App.WebForm1" %>
<!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 id="Head1" runat="server">
<style type="text/css">
.grid
{
margin-top: 50px;
}
</style>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<center>
<div>
<table>
<tr>
<td colspan="2" align="center">
<asp:Label ID="Label1" runat="server" Text="Sum Operation using LINQ" Font-Bold="true"
Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="Button1" runat="server" Text="Select Data" Font-Names="Verdana" Width="213px"
BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:GridView ID="GridView1" runat="server" CssClass="grid" BackColor="LightGoldenrodYellow"
BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None"
Width="184px">
<AlternatingRowStyle BackColor="PaleGoldenrod" />
<FooterStyle BackColor="Tan" />
<HeaderStyle BackColor="Tan" Font-Bold="True" />
<PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
<sortedascendingcellstyle backcolor="#FAFAE7" />
<sortedascendingheaderstyle backcolor="#DAC09E" />
<sorteddescendingcellstyle backcolor="#E1DB9C" />
<sorteddescendingheaderstyle backcolor="#C2A47B" />
</asp:GridView>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label2" runat="server" Text="Total Age:" Visible="false"></asp:Label>
</td>
<td>
<asp:Label ID="Label3" runat="server" Font-Bold="true" Font-Names="Verdana" Font-Size="Large"></asp:Label>
</td>
</tr>
</table>
</div>
</center>
</form>
</html>
Step 3: The complete code of WebForm1.aspx.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text;
namespace LINQ_Sum_App
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
var query = from r in objEntities.Employee select r;
GridView1.DataSource = query; GridView1.DataBind();
var querySum = from r in objEntities.Employee select new { Age = r.Age };
Label3.Text = query.Sum(p => p.Age).ToString();
Label2.Visible = true;
}
#region Instance MembersCompanyEntities objEntities = new CompanyEntities();
#endregion
}
}
Step 4: The output of the application looks like this:
![output-of-the-sum-application.jpg]()
Step 5: The data retrieved output of the application looks like this:
![retrieved-output-of-the-sum-application.jpg]()
Except Operation using LINQ
Question: What is an "except" operation?
In simple terms "It is used to produce the result set for the records not found in the succeeding tables".
Step 1: Create a new "ASP.NET Web Application", as in:
![Linq-Except-application.jpg]()
Step 2: The complete code of WebForm1.aspx looks like this:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="LINQExceptApp.WebForm1" %>
<!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 id="Head1" runat="server">
<style type="text/css">
.grid
{
margin-top: 50px;
}
</style>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<center>
<div>
<table>
<tr>
<td colspan="2" align="center">
<asp:Label ID="Label1" runat="server" Text="Except Operation using LINQ" Font-Bold="true"
Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="Button1" runat="server" Text="Select Data" Font-Names="Verdana" Width="213px"
BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:GridView ID="GridView1" runat="server" CssClass="grid" BackColor="LightGoldenrodYellow"
BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None">
<AlternatingRowStyle BackColor="PaleGoldenrod" />
<FooterStyle BackColor="Tan" />
<HeaderStyle BackColor="Tan" Font-Bold="True" />
<PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
<sortedascendingcellstyle backcolor="#FAFAE7" />
<sortedascendingheaderstyle backcolor="#DAC09E" />
<sorteddescendingcellstyle backcolor="#E1DB9C" />
<sorteddescendingheaderstyle backcolor="#C2A47B" />
</asp:GridView>
</td>
</tr>
</table>
</div>
</center>
</form>
</body>
</html>
Step 3: The complete code of WebForm1.aspx.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace LINQExceptApp
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
var queryEmp = from r in objEntities.Employee
select new
{
FirstName = r.FirstName,
LastName = r.LastName,
Age = r.Age
};
var queryTech = from p in objEntities.Techies
select new
{
FirstName = p.FirstName,
LastName = p.LastName,
Age = p.Age
};
var query = queryEmp.Except(queryTech);
GridView1.DataSource = query;
GridView1.DataBind();
}
#region Instance MembersCompanyEntities objEntities = new CompanyEntities();
#endregion
}
}
Step 4: The output of the application looks like this:
![output-of-the-Except-application.jpg]()
Step 5: The data retrieved output of the application looks like this:
![retrieved-output-of-the-Except-application.jpg]()