SPMetal LINQ - To SharePoint Delete 2010 Programmatically Using VS 2010


Introduction

 

Today, in this article let's play around with one of the interesting and most useful concepts in SharePoint 2010.

Question: What is a SPMetal LINQ to SharePoint Delete?

 

In simple terms "It enables creation of a DataContext object using SPMetal, by which we can delete the data of a custom list with the help of a LINQ query".

 

I think we are now good to go and implement this wonderful concept.

 

Step 1: Open the command prompt as an administrator and enter the following command by requesting a specific site:

 

Spmetal.exe /web:http://win-5d57sl2rvt1:9107/ /code:C:\Student.cs

 

After you have run this, the Student.cs file will be created in the C: Drive of your system directories.

 

Step 2: Open SharePoint 2010 central administration and navigate to specific site.

 

Step 3: Open up Visual Studio 2010 and create an "Empty SharePoint project":

Output1.gif

Step 4: Select "Deploy as a farm solution" and click the next button. Now an empty project will be created.

Output2.gif

 

Step 5: Add a new visual webpart for that project. Also add the Student.cs file into the project.

Output3.gif

 

Step 6: The complete code of visualwebpart1usercontrol.ascx looks like this:

 

<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %>

<%@ Assembly Name="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

<%@ Register TagPrefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls"

    Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

<%@ Register TagPrefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

<%@ Register TagPrefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>

<%@ Import Namespace="Microsoft.SharePoint" %>

<%@ Register TagPrefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages"

    Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

<%@  Control Language="C#" AutoEventWireup="true" CodeBehind="SPDeleteWPUserControl.ascx.cs"

    Inherits="SPMetalDeleteApp.SPDeleteWP.SPDeleteWPUserControl" %>

<center>

    <div>

        <table>

            <tr>

                <td colspan="2">

                    <asp:label id="Label1" runat="server" text="LINQ-TO-SharePoint Delete - SharePoint 2010 Programatically"

                        font-bold="true" font-size="Large" font-names="Verdana" forecolor="Maroon"></asp:label>

                </td>

            </tr>

            <tr>

                <td>

                    <asp:label id="Label7" runat="server" text="Please Enter ID" font-size="Large" font-names="Verdana"

                        font-italic="true"></asp:label>

                </td>

                <td>

                    <asp:textbox id="TextBox1" runat="server" width="117px"></asp:textbox>

                </td>

            </tr>

            <tr>

                <td colspan="2">

                    <br />

                    <asp:button id="Button1" runat="server" text="Delete Data" font-names="Verdana" width="282px"

                        backcolor="Orange" font-bold="True" onclick="Button1_Click" />

                </td>

            </tr>

            <tr>

                <td colspan="2">

                    <br />

                    <asp:label id="Label5" runat="server" font-bold="true" font-names="Verdana"></asp:label>

                </td>

            </tr>

        </table>

    </div>

</center>
 

Step 7: The complete code of visualwebpart1usercontrol.ascx.cs looks like this:
 

using System;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using Microsoft.SharePoint.Library;

using System.Linq;

using Microsoft.SharePoint.Linq;

namespace SPMetalDeleteApp.SPDeleteWP

{

    public partial class SPDeleteWPUserControl : UserControl

    {

        protected void Page_Load(object sender, EventArgs e)

        {

            TextBox1.Focus();

        }

        protected void Button1_Click(object sender, EventArgs e)

        {

            if (string.IsNullOrEmpty(TextBox1.Text))

            {

                Label5.Text = "Please Enter Some Values";

                Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                StudentDataContext dataContext = new StudentDataContext("http://win-5d57sl2rvt1:9107/");

                EntityList<PersonListItem> listItem = dataContext.GetList<PersonListItem>("PersonList");

                var delete = (from r in dataContext.PersonList where r.Id == int.Parse(TextBox1.Text) select r).First();

                listItem.DeleteOnSubmit(delete);

                dataContext.SubmitChanges();

                Label5.Text = "Data Successfully Deleted";

                Label5.ForeColor = System.Drawing.Color.Green;

                TextBox1.Text = string.Empty;

            }

        }

    }

}
 

Step 8: Deploy the solution file and add the created webpart to SharePoint site:

 

 

Step 9: The output of the person list looks like this:

Output4.gif 

 

Step 10: The output of the application looks like this:


Output5.png 

 

Step 11: The output of the data deleting application looks like this:


Output6.png

 

Step 12: The output of the data deleted in person list looks like this:

Output7.gif 

I hope this article is useful for you.