Techie Ideas

Sharepoint site 2010

2010-11-03T02:59:00.000-07:00

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How to Find Number of Columns in a Table

2010-03-19T11:21:00.000-07:00

Below script find out how many columns are there in a table

SELECT COUNT(1) 'No of Column(s)' FROM SYS.SYSCOLUMNS
WHERE ID = OBJECT_ID('TableName')

Happy Quering

Sleep for 1 min in SQL SERVER 2005

2010-03-19T06:43:00.001-07:00

We just want to delay our query for one min.

To achieve that one we need write the below script

print getdate()
waitfor delay '00:01'
print getdate()

Output:

Mar 19 2010 6:37PM
Mar 19 2010 6:38PM

Happy Querying

Multiple Columns as Primary Key - SQL Server 2005

2010-03-19T05:52:00.000-07:00

Steps to make multiple Columns of a table in SQL Server Management Studio

Go to Table Design.
Select a Column first to define it as Primary key.
To select multiple columns, hold down the CTRL key while you click the other columns.
Right-click the row selector for the column and select Set Primary Key.
A primary key index, named "PK_" followed by the table name is automatically created.

Hope this helps you

Happy Coding

Update Tables Using Inner Join

2010-03-17T05:15:00.000-07:00

You will come across the problem to update a table with the help of joining two tables.

Below is the steps to update a table using joins

Perform a update say UPDATE
Join the tables with condition say FIRSTTABLE AS A INNER JOIN SECONDTABLE AS B ON A.FIELDNAME = B.FIELDNAME
Write the condition which is going to change or update say SET A.FIELDNAME=2, B.FIELDNAME=5
If you have a where condition then add it say WHERE A.FIELDNAME=10

Combine the above steps and form a query as below
UPDATE
FIRSTTABLE AS A INNER JOIN SECONDTABLE AS B
ON A.FIELDNAME = B.FIELDNAME
SET A.FIELDNAME=2, B.FIELDNAME=5
WHERE A.FIELDNAME=10

Simply cool

Hope this helped you.

Happy Coding,
Kumar

Advantages and Disadvantages of LINQ

2010-02-04T12:32:00.000-08:00

LINQ (Language Integrated Query) is a Microsoft programming model and methodology that gives a formal query capabilities into Microsoft .NET-based programming languages.

It offers a compact, expressive, and intelligible syntax for manipulating data. The real value of LINQ comes is to apply the same query to an SQL database, a DataSet, an array of objects in memory and to many other types of data as well. It requires the presence of specific language extensions.

LINQ may be used to access all types of data, whereas embedded SQL is limited to addressing only databases that can handle SQL queries.

Below are the advantages and Disadvantages of LINQ

Advantages:

It is a cleaner and typesafety.
It is checked by the compiler instead of at runtime
It can be debugged easily.
It can be used against any datatype - it isn't limited to relational databases, you can also use it against XML, regular objects.
It can able to query not just tables in a relational database but also text files and XML files.

Disadvantages:

LINQ sends the entire query to the DB hence takes much network traffic but the stored procedures sends only argument and the stored procedure name. It will become really bad if the queries are very complex.
Preformance is degraded if we don't write the linq query correctly.
If you need to make changes to the way you do data access, you need to recompile, version, and redeploy your assembly.

Happy Coding and Learning

Convert Web Page to ASP.net User Control

2010-01-29T09:15:00.000-08:00

Some situation comes into picture where we want to change the web page to User control.

Steps to convert asp.net web page to user control.

Rename to the file extenstion (.aspx) to a .ascx extension.
Remove html, head, body, form tags from the page.
Change the "@ Page" directive to a "@ Control" directive.
Remove all attributes of the "@ Control" directive, except Language, AutoEventWireup, CodeFile, and Inherits.
Need to change the Inherits to have your new UserControl code behind file's name.
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="UserControlFilename.ascx.cs" Inherits="UserControlFileName" %>
Close and re-open the file to make squiggles go away.
Open the code behind file and change the class it inherits from to UserControl, and the class name to match your .ascx file.
public partial class UserControlFileName : System.Web.UI.UserControl

Hope this helps for some body.

What is Multi-Targeting in .net?

2010-01-27T00:24:00.001-08:00

In the previous version of Visual Studio, each Visual Studio release supports to a specific version of the .NET Framework. For example, VS 2002 only worked with .NET 1.0, VS 2003 only worked with .NET 1.1, and VS 2005 only worked with .NET 2.0.

Now with the major change in VS2008 is to support "Multi-Targeting "
Visual Studio 2008 is used to create projects that target .NET Framework version 2.0, 3.0, or 3.5. is what we call as "Multi-Targeting".

What is Tracing and how to enable it?

2010-01-12T04:20:00.000-08:00

Tracing helps understand which control uses more view state, start/end of PreInit etc. This type of information appears at the bottom of the page.

Tracing can be enable at Page level and Application Level

Page Level: You can add a Trace="true" in the page directive.
<%@ Page Language="C#" Trace="true" %>

Application Level: The user can enable Application level tracing in the Web.config file.
By doing this the user will get trace information for all pages in your application.

<configuration>
   <system.web>
   <trace enabled="true" />
   </system.web>
</configuration>

Happy Tracing.

C# 3.0 new Features - Part 2

2009-12-29T23:11:00.000-08:00

Continuing from part 1, here I will go one more step further and explain about Lambda Expression basics in C# 3.0 which will help us in writing a LINQ query.

Lambda Expressions - Part 1

In C# 2.0 we used to write anonymous delegate method that helped us in minimizing the code writing.

Example: The below code snippet that searches for a Employee based on the Empname field using predicates in C# 2.0

class Employee

{

private string empName;

public string EmpName

{

get

{

if (empName != null)

{

return empName;

}

set

{

empName = value;

}

Now we will get the employee details from GetAllEmployees() function which is written in Data Access Layer (DAL) Layer.

List <Employee> myEmployees = GetAllEmployees();

We will use System.Collection.List<T>.FindAll to search for the Employee based on EmpName.

MSDN has following information on the FindAll method.

Retrieves all the elements that match the conditions defined by the specified predicate.

For more information : http://msdn.microsoft.com/en-us/library/fh1w7y8z.aspx

We will now find the employee with the employee name filter.

List <Employee> employee = myEmployees.FindAll( new Predicate<Employee>(EmpNameFilter));

//Defination for EmpNameFilter

static bool EmpNameFilter(Employee e)

{

e.EmpName = “Kumar”

}

We will rewrite the above code using C# 2.0 Anonymous method.

List <Employee> employee = myEmployees.FindAll(delegate(Employee e) {return e.EmpName=”Kumar”})

We have reduced some coding steps with the help of anonymous method, we still able to reduce the coding steps with the help of Lambda Expression

List <Employee> employee = myEmployees.FindAll(e=>e.EmpName==”Kumar”);

So basically when we have a lambda expression defined then we are inherently using delegates. Its bit difficult for the first time but over a period of time we will feel happy using it.

Accoding to MSDN the following information for Lambda Expression.

A lambda expression is an anonymous function that can contain expressions and statements, and can be used to create delegates or expression tree types.

All lambda expressions use the lambda operator =>, which is read as "goes to". The left side of the lambda operator specifies the input parameters (if any) and the right side holds the expression or statement block. The lambda expression x => x * x is read "x goes to x times x." This expression can be assigned to a delegate type as follows:

delegate int del(int i);

static void Main(string[] args)

{

del myDelegate = x => x * x;

int j = myDelegate(5); //j = 25

}

The => operator has the same precedence as assignment (=) and is right-associative.

Lambdas are not allowed on the left side of the is or as operator.

Hope this article helps you to understand the basic about Lambda Expression.

Stay tuned for Lambda Expression Part 2.

Happy Coding and Leaning.

Static Class for Beginners

2009-12-26T03:19:00.000-08:00

In general, the members of a class can be accessed by instance of that class when they are in public, but there comes a situation to access or call members of a class without an instance and this can be achieved by declaring them as static.

How to create a static class and access in our application?

Step 1: Create a Static class name as "StaticExample"

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace KumarConsoleApplication
{
   public static class StaticExample
   {
   public static int AddNum(int num1, int num2)
   {
   return num1 + num2;
   }
   public static int SubNum(int num1, int num2)
   {
   return num1 - num2;
   }
   }
}

Step 2: Add reference of the above class in our application.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using KumarConsoleApplication;

namespace OurApplication
{
   class Program
   {
   static void Main(string[] args)
   {
   Console.WriteLine("Addition " + StaticExample.AddNum(10, 20));
   Console.WriteLine("Substraction " + StaticExample.SubNum(30, 10));
   Console.Read();
   }
   }
}

Step 3: Run the application and see the output in console application

The output is :

Addition 30

Substraction 20

Features:

Static classes can not be instantiated.

Static classes are sealed so they can not be inherited.

Static class is preceded by keyword static.

Static constructor of static class called only once.

Static class can have only static members which means only static members are allowed.

Static class has private constructors.

Member of the Static class can be accessed by class name itself.

Static classes can only have static constructor to initialize static members. class has private constructors.

Hope this article gave you some idea about static classes

Happy coding and learning

C# 3.0 New Features - Part 1

2009-12-23T03:38:00.000-08:00

Hi All,

Below are the new features of C# 3.0

1. Implicitly Typed Local Variables

C# 3.0 introduces a new keyword called "var". Var allows you to declare a new variable, whose type is implicitly inferred from the expression used to initialize the variable.This is a new and handy keyword that'll save you some typing. Example below:

// C# 2.0

int i = 10;

string str = "Hello Techies";

// New C# 3.0 var type

var i = 5;

var str = "Hello Techies";

The var keyword is NOT a completely new type, instead the compiler just takes a look at the right-hand side of the expression. If the right-hand side is an int, for example, the compiler will "replace" the var keyword with int. This means that the following contruction will NOT work:

// Will not work, 'cause the right-hand side of the var is unknown
var b;
b = 1556;

Some Restriction:

We cannot do the increment and decrement operation like i++ or ++i
We cannot declare the NULL value to the var variable
We cannot initialize the multiple var variables like others. Int I, j, k
2.Anonymous Types

C# 3.0 gives you the flexibility to create an instance of a class without having to write code for the class beforehand.

new { Name = "Kumar", Gender = "Male", Age = 25 };

In the background, the C# compiler would create a class that looks as follows:

class __Anonymous1

{

   private string _Name = "Kumar";

   private string _Gender = "Male";

   private int _Age = 20;

   public string Name {get { return _Name; } set { _Name = value; }}

   public string Gender {get { return _Gender; } set { _Gender = value; }}

   public int Age {get { return _Age; } set { _Age = value; }}

}

Now the user have a class, but the user still need something to hold an instance of the above class. This is where the "var" keyword comes in handy; it lets you hold a statically typed instance of the above instance of the anonymous type. Here is a rather simple and easy use of an anonymous type:

var employee = new { Name = "Kumar", Gender = "Male", Age = 25 };

3.Auto Implemented Property

This property plays significant role to set and get the values. In the previous versions we used to set the values to the temporarily local variable. Now it has been reduced in the C# 3.0 version. Because, .Net compiler will handle it implicitly

Let's see the new version, Auto implemented property.

[Access-modifier] data type [Name of the property]
{
get;
set;
}

For example we are going to create one property for Employee.

public string employeeID {get; set ;}
public string employeeName {get; set ;}
public int age {get; set ;}

In previous version we have done like this.

private string _employeeName;
public string employeeName
{
   get
   {
   return _employeeName;
   }
   set
   {
   _employeeName = value;
   }
}

Here in C# 3.0, it became auto implemented property, that means in the runtime, the .net compiler will assign the values to temp variable.

4.Object initializers
In C# 3.0 a new way to initialize objects. Example below:

// The old way
Employee emp = new Employee(); // Create object
emp.Name = "Kumar"; // Initialize property Name
emp.Gender = "Male"; // Initialize property Gender
emp.Age = 25; // Initialize property Age

// New way
Employee emp = new Employee { Name = "Kumar", Gender = "Male", Age = 25 };

This will also save some lines of code

Hope this article helps you.

Happy Learning and Coding
Kumar

SQL Database Offline / Online

2009-11-26T05:53:00.000-08:00

If the user wants to make the database offline or online below are the commands.

First Method:
To make database offline use the below query
ALTER DATABASE [Database name] SET OFFLINE

To make database online use the below query
ALTER DATABASE [Database name] SET ONLINE

Second Method:
User can also right click on the Database and select Tasks->Take Offline

select Tasks->Brink online for making Database to Online

Turn off Session State when not required

2009-11-25T22:41:00.000-08:00

Asp.net Session state is ON by default. Memory is lost even if we don't use this session state.
To improve the performance we need to turn off the session state when we are not in use.

Below are the different ways to turn off the session state.

If you don't want the session for your entire application then,turn off the session state in web.config file.<system.web>

<sessionState mode="Off"></sessionState>
If session is not required for few pages , then turn off the session state in page level.

<system.web>

<pages enableSessionState="false">
If you want to enable the session state for particular page

<%@ Page ... EnableSessionState="true" %>

What is "Microsoft Intermediate Language" (MSIL)?

2009-10-12T05:56:00.000-07:00

MSIL stands for Microsoft Intermediate Language. It can be called as Intermediate Language (IL) or Common Intermediate Language (CIL). During the compile time , the compiler convert the source code into Microsoft Intermediate Language (MSIL) .Microsoft Intermediate Language (MSIL) is a CPU-independent set of instructions that can be efficiently converted to the native code. During the runtime the Common Language Runtime (CLR)'s Just In Time (JIT) compiler converts the Microsoft Intermediate Language (MSIL) code into native code to the Operating systems.

When a compiler produces Microsoft Intermediate Language (MSIL), it also produces Metadata. The Microsoft Intermediate Language (MSIL) and Metadata are contained in a portable executable (PE) file . Microsoft Intermediate Language (MSIL) includes instructions for loading, storing, initializing, and calling methods on objects, as well as instructions for arithmetic and logical operations, control flow, direct memory access, exception handling, and other operations.

What do you mean by Web Service?

2009-10-12T03:45:00.000-07:00

The term Web services describes a standardized way of integrating Web-based applications using the XML, SOAP, WSDL and UDDI open standards over an Internet protocol backbone.

XML is used to tag the data
SOAP is used to transfer the data
WSDL is used for describing the services available
UDDI is used for listing what services are available

Used primarily as a means for businesses to communicate with each other and with clients, Web services allow organizations to communicate data without intimate knowledge of each other's IT systems behind the firewall.

What is Fragment Caching in ASP.NET?

2009-10-12T01:56:00.000-07:00

Fragment Caching in asp.net

Fragment caching refers to the caching of individual user controls within a Web Form.
Each user control can have independent cache durations and implementations of how the caching behavior is to be applied.
Fragment caching is useful when you need to cache only a subset of a page.

It is good to use in navigation bar,headers and footers.

Retain Web Browser Scroll Position After a Postback

2009-09-28T05:41:00.000-07:00

Following are the ways where the user can maintain the scroll position after a postback.

In the page declaration, add <%@ Page MaintainScrollPositionOnPostback="true" %> This will maintain the scroll position of that particular page only.
The user can even set via code behind also by including System.Web.UI.Page.MaintainScrollPositionOnPostBack = true;
The above two will maintain the scroll position for that page only. In order to maintain the scroll positions for the entire web site pages user has to add the Boolean attribute maintainScrollPositionOnPostBack="true" in Web.config file of <pages> section.

<pages

buffer="[True|False]"

enableEventValidation="[True|False]"

enableSessionState="[True|False|ReadOnly]"

enableViewState="[True|False]"

enableViewStateMac="[True|False]"

smartNavigation="[True|False]"

autoEventWireup="[True|False]"

pageBaseType="typename, assembly"

userControlBaseType="typename"

validateRequest="[True|False]"

masterPageFile="file path"

theme="string"

styleSheetTheme="string"

maxPageStateFieldLength="number"

compilationMode="[Always|Auto|Never]"

pageParserFilterType="string"

viewStateEncryptionMode="[Always|Auto|Never]"

maintainScrollPositionOnPostBack="[True|False]"

asyncTimeout="number"

</pages>

Open a URL in Internet Explorer using Process.Start

2009-09-28T05:29:00.000-07:00

You can use System.Diagnostics.Process.Start to launch Internet Explorer and open a web page.

The below code will open the specified URL in the default browser window.

string strWebLink = "www.techieideas.blogspot.com";
Process.Start("iexplore.exe", strWebLink);

The below code will open the specified URL in a new browser window.

string strWebLink = "www.techieideas.blogspot.com";
Process.Start(@"C:\Program Files\Internet Explorer\iexplore.exe", "-new " + strWebLink);

Sending eMail using SmtpClient class

2009-09-28T05:21:00.000-07:00

This sample code demonstrates how to send an email using the System.Net.Mail.SmtpClient class.

private bool sendMail(string strToAddress, string strFromAddress, string strSubject, string strBody)
{
// new instance of MailMessage
MailMessage mailMessage = new MailMessage();

// Sender Address
mailMessage.From = new MailAddress(strFromAddress);

// Recepient Address
mailMessage.To.Add(new MailAddress(strToAddress));

// Subject
mailMessage.Subject = strSubject;

// Body
mailMessage.Body = strBody;

// format of mail message
mailMessage.IsBodyHtml = true;

// new instance of Smtpclient
SmtpClient mailSmtpClient = new SmtpClient("smtpServer");

// mail sent
mailSmtpClient.Send(mailMessage);
}