What is LINQ and why it’s
useful in LINQ
LINQ is Language integrated Query Language. It’s part of
.Net framework, you can easily integrate this with SharePoint 2010. It’s used to
Query on Data sources such as Object, Datasets, SQL, XML and other entities.
LINQ provide access to sharepoint in TYPED Manner, you can easily access List
columns name as property. As syntax is same as it is for .net development.
var items = from s in DataContext.Students
select s;
SPMetal
SPMetal is tool provided by sharepoint , used to created entity
model for sharepoint site objects. You can write these classes manually as
well, but its very time consuming task. It will create partial class at
specified location, you can simply add these classes in your project.
Simple CRUD operation
using LINQ for SharePoint List
Step 1: Create List
Create a simple list in sharepoint site .i have created Custom
List with the name of students(Title, firstname,lastname, Country).
Step 2: Generate Entity model.
Open command line -> start -> type cmd in search box
-> open Command Line.
Type CD C:\Program Files\Common Files\Microsoft
Shared\Web Server Extensions\14\BIN
This is path for SPMetal.exe
It
will create entities classes for you. Go to given path in command to verify.
Step 3:
Create Visual WebPart.
Open Visual studio 2010 and Create new sharepoint 2010
visual webpart project,
File -> New -> Project -> Sharepoint - >2010 -> Visual web part . Give its appropriate
name and location and press OK.
Visual webpart work
as form solution so next you have to verify your site url and press ok.
Visual studio load
its project structure.
Now you have to add
reference for LINQ.
Right Click on Project (Solution Explorer) -> Add Reference -> Select
Microsoft.Sharepoint.LINQ
In code Behind of Webpart, add following Namespaces
using System.Linq;
using Microsoft.SharePoint.Linq;
using Microsoft.SharePoint;
In visual web part you can simple trag and drop control to
perform your operation.
After creating form design you have to move in code behind .
(.CS file of webpart)
I have written these
four methods to perform CRUD Operation
#region CRUD
Operation using LINQ
/// <summary>
/// Delete the student
/// </summary>
/// <param name="objTitle"></param>
public void
DeleteStudent(string objTitle)
{
try
{
using (MyEntitiesDataContext
dc = new MyEntitiesDataContext(SPContext.Current.Site.Url))
{
EntityList<StudentsItem> listItems = dc.GetList<StudentsItem>("Students");
var updateobj = (from c in listItems
where c.Firstname == objTitle
select c).First();
dc.Students.DeleteOnSubmit(updateobj);
//Submit the changes
dc.SubmitChanges();
}
}
catch (Exception
ex)
{
Response.Write(ex.Message);
}
}
/// <summary>
/// Insert Student
/// </summary>
public void
InsertStudent()
{
try
{
using (MyEntitiesDataContext
dc = new MyEntitiesDataContext("http://sp2010-sana/"))
{
EntityList<StudentsItem> listItems = dc.GetList<StudentsItem>("Students");
StudentsItem objnew = new StudentsItem()
{
Firstname =
txtFname.Text.Trim(),
Lastname =
txtLname.Text.Trim(),
Country = Country.USA,
Title =
txtTitle.Text.Trim()
};// Insert the new list item to the list
dc.Students.InsertOnSubmit(objnew);
dc.SubmitChanges();
}
}
catch (Exception
ex)
{
throw;
}
}
/// <summary>
/// Update items
/// </summary>
/// <param name="objTitle"> title for the Item</param>
public void
UpdateStudent(string objTitle)
{
try
{
using (MyEntitiesDataContext
dc = new MyEntitiesDataContext("http://sp2010-sana/"))
{
EntityList<StudentsItem> listItems = dc.GetList<StudentsItem>("Students");
StudentsItem updateobj = (from c in listItems
where c.Id == 4
select c).First();
updateobj.Lastname = "Item2";
updateobj.Firstname = "Item2";
txtLname.Text = updateobj.Id.ToString();
dc.Students.InsertOnSubmit(updateobj);
dc.SubmitChanges();
}
}
catch (Exception
ex)
{
Response.Write(ex.Message + "</br>");
}
}
#endregion
I have Created one Grid View to Show all the students. So in
in Page Load I have just added data source to Gridview. You can see one more method name as Register
Events() , I have used it to register all events (such as I am using 2 buttons
(btnsave and btndelete))
protected void
Page_Load(object sender, EventArgs e)
{
using (MyEntitiesDataContext
dc = new MyEntitiesDataContext(SPContext.Current.Site.Url))
{
var items = from
s in dc.Students
select s;
GridView1.DataSource = items;
GridView1.DataBind();
}
RegisterEvents();
}
public void
RegisterEvents()
{
btnSave.Click += new EventHandler(btnSave_Click);
btnDelete.Click += new EventHandler(btnDelete_Click);
}
Visual Web part Designer Code,
<%@ 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="StudentdropDownUserControl.ascx.cs"
Inherits="LINQ_Visual_Web_Part.StudentdropDown.StudentdropDownUserControl"
%>
<table class="style1">
<tr>
<td>
Title</td>
<td>
<asp:TextBox ID="txtTitle"
runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
first Name</td>
<td>
<asp:TextBox ID="txtFname"
runat="server"
></asp:TextBox>
</td>
</tr>
<tr>
<td>
Last Name</td>
<td>
<asp:TextBox ID="txtLname"
runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
Country</td>
<td>
<asp:DropDownList ID="DropDownList1"
runat="server">
</asp:DropDownList>
</td>
</tr>
<tr>
<td>
</td>
<td>
<asp:Button ID="btnSave"
runat="server"
Text="Save"
Width="123px"
/>
</td>
</tr>
<tr>
<td>
</td>
<td>
<asp:Button ID="btnDelete"
runat="server"
Text="Delete"
/>
</td>
</tr>
</table>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
BackColor="White"
BorderColor="#999999"
BorderStyle="Solid"
BorderWidth="1px"
CellPadding="3"
EnableModelValidation="True"
ForeColor="Black"
GridLines="Vertical"
>
<AlternatingRowStyle
BackColor="#CCCCCC" CssClass=”alternateItemStyle”/>
<Columns>
<asp:BoundField DataField="Title"
HeaderText="Title"
/>
<asp:BoundField DataField="firstname"
HeaderText="First
name" />
<asp:BoundField DataField="Lastname"
HeaderText="Last
name" />
</Columns>
<FooterStyle BackColor="#CCCCCC"
/>
<HeaderStyle BackColor="Black"
CssClass=”headerStyle”
Font-Bold="True"
ForeColor="White"
/>
<PagerStyle BackColor="#999999"
ForeColor="Black"
HorizontalAlign="Center"
/>
<SelectedRowStyle
BackColor="#000099"
Font-Bold="True"
ForeColor="White"
/>
</asp:GridView>
Deploy to sharepoint.
Build the project to verify that you don’t have any syntax
error.
If you have sharepoint on your Visual studio machine then
you can simply
Right Click on Project -> Deploy. Otherwise select
package option it will create .wsp solution file ,
Adding webpart in
sharepoint
Go to any page (must have webpart zone option) -> Add
Webpart -> Choose Custom Category -> your newly born webpart will be
there, select this webpart. Now you can test functionality.y
You can Download Complete
Here
Your comments are really appreciated and more helpful for me
to writing more and in best way.
