Sunday, August 29, 2010

LinqDatasource A Great Control for declarative programming

I have used data source control many times and its great it provides us great features for declarative binding. LinqDataSource Control is a great control and it allows us to bind linq queries without writing any code declaratively. Let’s create a example in that example I am not going to write a single line of code and we are going to create view,Update and Delete functionality.

So first we need a table which will have data. So, I am going to use the same table which I have used in my old posts. Below is the table structure for this example.

Table Structure of Linq Data Source Example

Let’s insert some data for that table structure. I have already inserted it in previous example. Just like below.

Table data for linq to SQL Linq Data source example

Now, To bind a linqdatasource we need a Linq-To-SQL Data context class Let’s create it via Project->Right Click->Add New Item –>Go to data tab->Linq-To-SQL classes Just like following.

Add new Linq-To-SQL Classes

After that I have just dragged user data to my data context just like following.

Dragging Table to Linq-to-SQL classes

After creating Our Linq-To-SQL Classes Let’s just Add the A grid View control to my default.aspx page and apply some default format like this.

Adding a GridView from ToolBox and applying format

Now Let’s add a LinqDataSource from the toolbox like following.

Creating A Linq Data Source from ToolBox

Now select the data source and click configure data source as we can see as below.

Configuring Linq Data Source

After clicking on the Configure Data source a wizard will appear which will allow us to select Linq-to-SQL Context class just like following.

Select Linq-To-SQL Class for Linq Data Source

After clicking on next it will allow us to select the Linq-To-SQL Table. In our case it is a Users table so select user table just like following and select * for all columns.

Selecting Linq-To-SQL Table

Click finish now our Linq Data Source is Ready Now select the grid view and select Linq Data source we just created like below.

Setting up Grid view data source as linq datasource

Now our grid view is ready We just need to select Enable Sorting and Enable Paging to give default sorting and paging functionality to grid view. Now do to aspx file and you will see that grid view control is created. I have set two more properties AutoGenerateDeleteButton and AutoGenerateEditButton property of grid view to true as we need to create update and delete functionality also. Just like below.

<asp:GridView ID="GridView1" runat="server" CellPadding="4" ForeColor="#333333"
GridLines="None" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" DataSourceID="LinqDataSource1"
AutoGenerateDeleteButton="True" AutoGenerateEditButton="True"
DataKeyNames="UserId" >
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="UserId" HeaderText="UserId"
SortExpression="UserId" ReadOnly="True" />
<asp:BoundField DataField="UserName" HeaderText="UserName"
SortExpression="UserName" />
<asp:BoundField DataField="FirstName" HeaderText="FirstName"
SortExpression="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="LastName"
SortExpression="LastName" />
</Columns>
<EditRowStyle BackColor="#2461BF" />
<FooterStyle BackColor="#507CD1" Font-Bold="True"
ForeColor="White" />
<HeaderStyle BackColor="#507CD1" Font-Bold="True"
ForeColor="White" />
<PagerStyle BackColor="#2461BF" ForeColor="White"
HorizontalAlign="Center" />
<RowStyle BackColor="#EFF3FB" />
<SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True"
ForeColor="#333333" />
<SortedAscendingCellStyle BackColor="#F5F7FB" />
<SortedAscendingHeaderStyle BackColor="#6D95E1" />
<SortedDescendingCellStyle BackColor="#E9EBEF" />
<SortedDescendingHeaderStyle BackColor="#4870BE" />
</asp:GridView>
Then go to Linq Data source and set EnableDelete and EnableUpdate property to true as we need this functionality. Just like following.

<asp:LinqDataSource ID="LinqDataSource1" runat="server"
ContextTypeName="Blog.MyBlogDataContext"
EntityTypeName="" TableName="Users"
EnableDelete="True" EnableUpdate="True">
</asp:LinqDataSource>
That’s it now everything is ready lets run the example and see how its works here is the update example and its working fine as should.

Ouput Of Linq Data Source Control

So It’s very easy to create this kind of functionality. Hope this help you.. Happy Programming..

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Calling an asp.net web service from jQuery

As I have post it in earlier post that jQuery is one of most popular JavaScript library in the world amongst web developers Lets take a example calling ASP.NET web service with jQuery . You will see at the end of the example that how easy it is to call a web service from the jQuery.

Let’s create a simple Hello World web service. Go to your project right click->Add –> New Item and select web service and add a web service like following.
Adding  a webservice
Now modify the code of web service like following.

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script,
using ASP.NET AJAX, uncomment the following line.
[System.Web.Script.Services.ScriptService]
public class HelloWorld : System.Web.Services.WebService
{
[WebMethod]
public string PrintMessage()
{
return "Hello World..This is from webservice";
}
}

Here please make sure that [System.Web.Script.Services.ScriptService] is un commented because this attribute is responsible for allowing web service to be called by Client side scripts.

Now to call this web service from jquery we have to include jQuery Js like following. I am already having in my project so i don’t need to include in project just need to add script tag like following.

<script type="text/javascript" src="Scripts/jquery-1.4.1.min.js">
</script>

Now let’s add some JavaScript code to call web service methods like following.

<script language="javascript" type="text/javascript">
function CallWebServiceFromJquery() {

$.ajax({
type: "POST",
url: "HelloWorld.asmx/PrintMessage",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: OnSuccess,
error: OnError
});

}

function OnSuccess(data, status)
{
alert(data.d);
}

function OnError(request, status, error)
{
alert(request.statusText);
}
</script>

Here I have written three functions in JavaScript First one is CallWebserviceFromJquery which will call the web service. The another two functions are delegates of webservice if Success is there then onSuccess Method will be called and If Error is there then OnError method will be called.

Inside the CallWebserviceFromJquery I have passed some parameter which will call web service with Ajax capabilities of $ jQuery object. Here are the description for each parameter.

Type: This can be GET or POST for web service we have to take POST as by default web service does not work with GET to prevent Cross site requests.

Url: Here will be url of the webservice. You have insert fully qualified web service name here.

Data:Here it will be Empty as we not calling web service with parameters if you are calling web service with parameter then you have to pass that here.

ContentType: here you have to specify what type of content is going to return by web service.

Datatype:Json it will be result type.

Sucess:Here I have called the OnSuccess when the call is complete successfully. If you check the OnSuccess method you will see that I have set the returned result from the web service to the label. In the OnSuccess method body you see ‘data.d’. The ‘d’ here is the short form of data.

Error: Same as I have done with OnSuccess. If any error occurred while retrieving the data then the OnError method is invoked.

Now let’s add a asp.net button for on client click we will call the javascript function like following.

<asp:Button ID="btnCallWebService" runat="server"
OnClientClick="CallWebServiceFromJquery()"
Text="Call Webservice"/>

Now Let’s run it and here is the output in browser.

Ouput
Hope this will help you!!!.. Happy programming..

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Friday, August 27, 2010

jQuery- JavaScript Library Write less do more

This is introductory post jQuery an open source JavaScript library. I know what you guys thinking and I also know that jQuery does not required introduction. It is so much popular and most of web developers whether they are developing using asp.net,php,Jsp or any language on web they are using jQuery but this post is for who is not aware of it and or they are new to the web based programming.

We all are using JavaScript for client side scripting language almost 95% percentage of web application uses JavaScript as client script. We do lots of things with JavaScript right from the alerts to validation of controls to animation and now days we calling web services from JavaScript and fetching server side data also and rendering them into browser. If you are using JavaScript then you are following some patterns like selecting a element on and then perform some operation on that element on client side like do validation of controls or changing the style sheet of that element or animating them etc. jQuery help you doing this in rather simpler way so you can save lots of time doing other things instead of writing long complex JavaScript.

Why jQuery?

jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. jQuery is designed to change the way that you write JavaScript. jQuery provides lots of functionality like animating elements,Ajax interaction with server sides web service, changing CSS of a Elements etc and you can complete those task in minimum line of the code. For example let’s see the code which are given Homepage of jQuery website.

$("p.neat").addClass("ohmy").show("slow");
Above code kind enough to animate a particular Div in Animating way. If you write this kind of code in normal JavaScript then it will take much time and dozens of line of code. Here you can do simply that in one line of code. So, I would highly recommend every web developers to use jQuery instead of regular JavaScript.

Use Full Links For jQuery

If you want to learn jQuery then following are links which can be useful to you.

http://docs.jquery.com/How_jQuery_Works- For How jQuery Works

http://jquery.org/history- For History of jQuery

http://docs.jquery.com/Main_Page- jQuery documentation

Hope this will help you!!! Happy programming..

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Tuesday, August 24, 2010

Using Let Keyword in Linq

I am using Linq-To-Object in my current project to remove some extra loops and I have found one of the great keyword in Linq called ‘Let’. Let keyword provides facility to declare a temporary variable inside the Linq Query.We can assign the result of manipulation to temporary variable inside query and we can use that temporary variable to another manipulation.

Let’s take a simple example of Linq query I am using an integer array to find square and after finding the square of the integer value I will use let keyword to find square value which are greater then 20. Here is the my query for that.

protected void Page_Load(object sender, EventArgs e)
{

int[] intArray = { 1, 2, 3, 4, 5, 6, 7, 8 };
var Result = from i in intArray
let square = i * i
where square>20
select square;
foreach (int i in Result)
{
Response.Write(i.ToString());
Response.Write("\n");
}
}
Here is the result of that query as expected.
LetResult

Let keyword is more useful when you are working with directories and files,xml manipulations so here possibilities are unlimited. Hope this will help you.. Happy Programming!!!

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Wednesday, August 18, 2010

Entity Framework 4.0- Bind Stored Procedure with Result Entity class

Microsoft Entity Framework version 4.0 is a brand new ORM(Object Relational Mapper) from Microsoft. It’s provides now some new features which are not there in the earlier version of Entity framework. Let’s walk through a simple example of a new features which will create a new Entity class based on stored procedure result. We will use same table for this example for which they have used earlier for Linq Binding with Custom Entity.

Below is the table which have simple fields like first name,last name etc.

SQL Table for Entity Example.

Let’s insert some data like following.

Sample data for Entity Framework Example

Below is the stored procedure which I am going to use for this example which will simply fetch data from the table.

CREATE PROCEDURE dbo.GetAllUsers

AS
SET NOCOUNT ON
SELECT
UserId,
UserName,
FirstName,
LastName,
FirstName + ' ' + LastName AS [FullName]

FROM dbo.Users
Now let’s create Entity model class just like below via Project->Add New Item->Go to Data tab and then select ADO.NET Entity Data Model.

Adding a New Enity model class for Entity Framework example

Once you click add a dialog box will appear which will ask for Data Model Contents there are two options Generate From Database and another one is Empty Model. Generate from database will create a Entity model from the ready made database while Empty model enable us to create a model first and then it will allow us to create a database from our model. We are going to use Generate From database for this example. Select Generate From Database like following and click Next.

Generating Model from database for Entity Framework 4.0 Example

After click on the next it will ask for database connection string like following where you need to apply connection string for that. I am already having connection string in my web.config so i just selected like below otherwise you need to create one via clicking on new connection. Also you need to specify the connection string name in web.config so it will put a connection string in connection string section with that name.

MyConnection

Once you click next it will fetch the all database objects information like Tables,Views and Stored Procedure like following. Here our purpose is to work with stored procedure so I just selected the stored procedure and selected the GetAllUsers Stored Procedure.

Selecting Stored procedure

After that it will create a Entity Model class in solution explorer.Now we want to bind the stored procedure with result class so first we need to create function which will call ‘GetAllUser’ stored procedure. To create function we just need to select Our Entity Model class and then go to Model Browser and select the Stored Procedure and right click->Add Function Import like following image.

Importing a function from stored procedure example.

It will start a new wizard and will go to next step like following image which will have four options 1. None 2. Scalars 3. Complex 4. Entities and there will be a button Get Column information once you click it. It will gather all the column information of stored procedure result set and then click ‘Create New Complex Type’ It will create a new complex type from the gathered column information.

Gathering a column info and then

You can also rename that class so I have renamed the class as ‘User Info’ like following.

UserInfo

Now click ok and now it will create function which call the stored procedure and will return Object Result set of Type ‘UserInfo’ which we have just created. Now let’s bind that to a simple grid view to see how its works. So Let’s take a simple grid view like below.

<asp:GridView ID="grdUserList" runat="server">
</asp:GridView> 
Now Let’s bind that grid view like following from the code behind file of asp.net like following.

protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
using (BlogEntities myEntity = new BlogEntities())
{
grdUserList.DataSource = myEntity.GetAllUsers();
grdUserList.DataBind();
}
}

}
Just run it with Ctrl + F5 and below it the output in browser.

Output of Entity Framework 4.0 Example

That’s it very easy and simple to bind complex type with stored procedure using ADO.NET Entity Framework 4.0. Hope this will help you.. Happy Programming!!!

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Tuesday, August 3, 2010

Binding A Custom Entity Class to stored procedure using Linq-To-SQL

I have already written several post about Linq its a great ORM that we can use in various way. The purpose of this post to demonstrate How we can bind custom entity to stored procedure result with use of Linq-To-SQL. Let’s go through it and you will realize that how easy it will be to bind a Custom Entity to Stored Procedure result.

Let’s first create a simple table to which will hold the user data. It will contain four field like UserId,UserName,FirstName and LastName like following.

SQLTable

Now let’s insert some data into the table like following. SQLTableData

Now let’s create a stored procedure which will return the table data and a new field called Full Name like following. Here full name is a combination of first name and last name

CREATE PROCEDURE dbo.GetAllUsers

AS
SET NOCOUNT ON
SELECT
UserId,
UserName,
FirstName,
LastName,
FirstName + ' ' + LastName AS [FullName]

FROM dbo.Users
After creating a stored procedure it time to create a Linq-To-SQL Right Click Project->Add New Item and Go To->Data and Add LINQ to SQL Classes called MyBlogDataContext.dbml.After creating datacontext class for Linq just drag above store procedure to Linq-To-SQL classes and it will create a function like following.

StoredProcedureInLinqClass

Now let’s add a New Entity Class called UserInfo into Linq-To-SQL DataContext via Right Click Add New Class Just like following.AddClass

After adding class I have added same property as its having in user table and Hence our UserInfo Class will look like following.

UserInfoClass

Now everything is ready Custom Entity Class called UserInfo and we have Our Function ready which will return Stored Procedure output. Here Linq-To-SQL Provides a property called ReturnType If you select function which we have created via dragging a stored procedure in data context class. We just need to select our UserInfo class there just like following and it will bind the stored procedure with that particular UserInfo class. here only condition should be satisfied that Our Custom Entity class should contain all the field with compatible .NET Data types which will return the data. Below is the property which we are talking about.

SelectProperty

Now let’s add grid view to default.aspx page like following and Let’s bind output of stored procedure to that grid view.
<asp:GridView ID="grdUserList" runat="server">
</asp:GridView> 
After placing the Grid View in page here is the code for biding grid view in default.aspx page_load event.
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
using (MyBlogDataContextDataContext myContext =
new MyBlogDataContextDataContext())
{
List<UserInfo> MyUserList =
myContext.GetAllUsers().ToList<UserInfo>();
grdUserList.DataSource = MyUserList;
grdUserList.DataBind(); 
}
}
}
And here is the output which we get in browser after running our web application.

Ouput

That’s it its very easy.. Hope this will help you…

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Sunday, August 1, 2010

Visual Studio –>Add Database –> Named pipe Provider Error for SQL Server

Recently I have been working on a article for my blog for that I just tried to add a database file on my solution with visual studio and I have received following error.

An error has occurred while establishing a connection to the server.
(provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 5)
An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2008, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 1326)

After checking my configuration I have found that in my machine there was more then one instance of SQL Server and the Default Instance was not properly configured and that’s why I am getting this error. This error was occurred because my Default Instance of SQL Server Express was not having TCP/IP Protocol Enabled. So I have enabled it just like following.

Go to All Programs->Microsoft SQL Server 2008-> Configuration Tools –>SQL Server configuration manager. It will open up windows like following.

SQLServerConfiguration

After that Go To SQL Server Network Configuration and Select Protocols for your default instances and then enabled TCP/IP like following and that’s it. Now error is resolved.

SQL Server TCP/Ip Protol configuration
Hope this will help you…

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TSQL Challenges on beyondrelational.com

My friend and Guide Jacob Sebastian who is an Microsoft SQL Server MVP running a very popular series of TSQL on his site beyondrelational.com. If you know something about SQL Server then this challenge is for you. And if you are master of SQL then this challenge is for you to test you knowledge. If you have some time and If you want to test you knowledge or you want enhance your knowledge challenge then please spare some time to take it. Here is link for that.

http://beyondrelational.com/blogs/tc/archive/2010/07/26/tsql-challenge-35-find-the-total-number-of-full-attendees-in-each-24-hop-session.aspx

Currently he is running TSQL Challenge Number 35 which is about fine number full attendee for a conference.

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