Difference Between Where and Having Clause

The WHERE clause does not work with aggregates like SUM,Count etc.

The SQL above will not work, because the where clause doesn’t work with aggregates – like sum, avg, max, etc.. Instead, what we will need to use is the having clause. The having clause was added to sql just so we could compare aggregates to other values – just how the ‘where’ clause can be used with non-aggregates. Now, the correct sql will look like this:

Many time i have seen code where Having and where clause are misused see Examples Below -

BAD SQL:
select employee, sum(bonus) from emp_bonus
group by employee where sum(bonus) > 1000;

GOOD SQL:
select employee, sum(bonus) from emp_bonus
group by employee having sum(bonus) > 1000;


Difference between having and where clause

So we can see that the difference between the having and where clause in sql is that the where clause can not be used with aggregates, but the having clause can. One way to think of it is that the having clause is an additional filter to the where clause.

Sql Standard Theory says WHERE Clause restricts the result set before returning rows and HAVING restricts the result set after retrieving all records.That's why WHERE is faster as compared to Having and that's why having is not used more commonly or always as that of Having so it should used in circumstances where it is necessary to use having and nothing else is possible like as in case we are using aggregate functions

Difference Between System.Web and System.WebServer

System.web is the settings section for IIS6 and the built in cassini server (the test server in Visual Studio 2010 and before where you are targeting asp.net 3.5 or lower)

The system.webserver is a child of the configuration section that means in web.config file <system.webserver> tag is placed under
<configuration> Tag.

System.WebServer Tag is contained in web.config file in root directory of website. This file contains configuration that needs to be implemented on IIS for Current project. Configuration coded in <system.webserver> Tag are implemented on IIS and are only applied to Project or Webapplication to which corresponding web.config Belongs. This Tag Can Exist is one of below formats in your project's web.config file in root directory of Web Application.

Empty <system.webserver> Tag Under <configuration> Tag -

<configuration>
  <system.webServer>
  </system.webServer>
</configuration>

The system.web section is used in web.config file of Asp.net WebApplications for defining Server Configuration that are applicable for IIS 6, while the system.webserver version is used to configure IIS 7.0. IIS 7.0 includes a new ASP.NET pipeline and some configuration differences. you can check complete details on link below -

https://msdn.microsoft.com/en-us/library/bb763179.aspx


System.webserver is the Server Configuration section for IIS 7 and above, and the build in IIS Express server which is used in Visual Studio 2010 targeting asp.net 4 and any newer versions that are released in the future.

Sample of Web.config file Contains Both <system.web> and <system.webserver>

<?xml version="1.0"?>
<!--
    Note: As an alternative to hand editing this file you can use the
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in
    machine.config.comments usually located in
    \Windows\Microsoft.Net\Framework\v2.x\Config
-->
<configuration>
<appSettings>
<add key="username" value="admin-heemanshu@564496"/>
<add key="password" value="@htennty50!334#"/>
</appSettings>

<connectionStrings/>

<system.web>
<!--
            Set compilation debug="true" to insert debugging
            symbols into the compiled page. Because this
            affects performance, set this value to true only
            during development.

            Visual Basic options:
            Set strict="true" to disallow all data type conversions
            where data loss can occur.
            Set explicit="true" to force declaration of all variables.
        -->
<compilation debug="true" strict="false" explicit="true"/>
<pages>
<namespaces>
<clear/>
<add namespace="System"/>
<add namespace="System.Collections"/>
<add namespace="System.Collections.Specialized"/>
<add namespace="System.Configuration"/>
<add namespace="System.Text"/>
<add namespace="System.Text.RegularExpressions"/>
<add namespace="System.Web"/>
<add namespace="System.Web.Caching"/>
<add namespace="System.Web.SessionState"/>
<add namespace="System.Web.Security"/>
<add namespace="System.Web.Profile"/>
<add namespace="System.Web.UI"/>
<add namespace="System.Web.UI.WebControls"/>
<add namespace="System.Web.UI.WebControls.WebParts"/>
<add namespace="System.Web.UI.HtmlControls"/>
</namespaces>
</pages>

<!--
            The <authentication> section enables configuration
            of the security authentication mode used by
            ASP.NET to identify an incoming user.
               -->

<authentication mode="Windows"/>

<!--
            The <customErrors> section enables configuration
            of what to do if/when an unhandled error occurs
            during the execution of a request. Specifically,
            it enables developers to configure html error pages
            to be displayed in place of a error stack trace.-->
<customErrors mode="Off" defaultRedirect="GenericErrorPage.htm">
<error statusCode="404" redirect="FileNotFound.htm"/>
</customErrors>
</system.web>
 
      <system.webServer>
       <rewrite>
        <rules>
          <rule name="Redirect" patternSyntax="ECMAScript" stopProcessing="true">
            <match url=".*" />
            <conditions>
                <add input="{HTTP_HOST}" pattern="^xyz.com$" />
            </conditions>
            <action type="Redirect" url="http://www.xyz.com/{R:0}" />
         </rule>
       </rules>
     </rewrite>
    </system.webServer>

</configuration>

Difference Between http get and jsonp

An HTTP GET request is what you get when you enter a URI in your browser or when you click on a link on a web page. Certain HTML elements, like also generate GET requests. GET requests a resource from the server. You can pass additional information to a server-side script by adding 'query parameters' after the script, such as Example Domain.

Say you're on domain www.example.com, and you want to make a request to domainwww.example.net. To do so, you need to cross domain boundaries, a no-no in most of browserland.

Enter JSONP. When you make your request to a server that is JSONP enabled, you pass a special parameter that tells the server a little bit about your page. That way, the server is able to nicely wrap up its response in a way that your page can handle.

For example, say the server expects a parameter called "callback" to enable its JSONP capabilities. Then your request would look like:

http://www.example.net/sample.aspx?callback=mycallback

Without JSONP, this might return some basic JavaScript object, like so:

{ foo: 'bar' }

However, with JSONP, when the server receives the "callback" parameter, it wraps up the result a little differently, returning something like this:

mycallback({ foo: 'bar' });

As you can see, it will now invoke the method you specified. So, in your page, you define the callback function:

mycallback = function(data){ alert(data.foo); };

Major issue with JSONP

you lose a lot of control of the request that creates doubts in maintaining security

Angularjs Vs Jquery

Answer Angularjs Vs Jquery On Quora 
Angularjs Vs Jquery

jQuery will be used for things like higher level APIs, updating DOM elements, adding classes and wrapping XHR calls up nicely. Angular 1.x actually uses jQuery lite (jQLite) inside itself, or can use the full jQuery library if it's present before Angular at runtime. Using jQuery with Angular will unleash more power to Angular core as it knows you're using it, so it binds onto jQuery and passes you the full jQuery API instead of it's built-in jQLite.Remember that Angular is a data-binding MVVM framework, of which jQuery is not.

See The Major Benefits in Angular JS as Compared To Jquery

Below is Table List of Difference between jquery and Angularjs . See the Point search what that point means then analyze do you need the power or usage of that point in the project . On the basis of that Analyze Which one of them you need in your project

Difference between on and bind in jQuery

The .bind() method registers the event and event handler directly to the DOM element.This method is still very handy when wiring-up event handlers, but there are various performance concerns as are listed below.
Internally .bind() maps to .on() as per current version of Jquery .bind may be removed from future versions at any time. There is no reason to keep using .bind and every reason to prefer .on instead.
The .bind() method will attach the event handler to all of the anchors that are matched! That is not good. Not only is that expensive to implicitly iterate over all of those items to attach an event handler, but it is also wasteful since it is the same event handler over and over again.

Problems

1. The method attaches the same event handler to every matched element in the selection.
2. It doesn’t work for elements added dynamically that matches the same selector.
3. There are performance concerns when dealing with a large selection.
4. The attachment is done upfront which can have performance issues on page load.

The on() method as being “overloaded” with different signatures, which in turn changes how the event binding is wired-up. The .on method bring a lot of consistency to the API and hopefully makes things slightly less confusing.

Cons 1. Brings confusion because the behavior changes based on how you call the method.

Grunt vs Gulp

• Gulp and Grunt are both Automated Task Runner . Major Difference Between Gulp and Grunt Lies in How They Deal With Automation of Tasks Internally .
  
  Gulp Uses Node Streams For running different tasks and Grunt use temp files for the same work .
• Grunt runns tasks using Temporary files which are disk I/O operations. Your SASS file is compiled and then written to a temporary file. The temporary file is used by the autoprefixer and then the final product is written to the destination file.
  
  Working of Grunt
  
  Gulp runs task all in main memory. Your SASS file is compiled in main memory, then the result is passed to the autoprefixer without being written to a file and the destination file is then written out.
  
  Working of Gulp
• In-memory operations are faster as compared to disk writes which means that Gulp has a big speed advantage.
• Speed Comparison Of Gulp Vs Grunt Can be Found Here - http://tech.tmw.co.uk/2014/01/speedtesting-gulp-and-grunt/
• Speed Difference
  
  
  
  Source : http://tech.tmw.co.uk/2014/01/speedtesting-gulp-and-grunt/

Difference Between Bower and NPM

• Npm and Bower are both Project dependency management tools. But the main difference between both is npm is used for installing Node js modules but bower js is used for managing front end components like html,css,js etc.

• npm is most commonly used for managing Node.js modules, but it works for the front-end too when combined with Browserify etc

• Bower is front-end Package Manager. The biggest difference is that npm does nested dependency tree that increases its size eventually while Bower requires a flat dependency tree No nested versioning of Packages

NESTED DEPENDENCY TREE
A nested dependency tree means the dependencies or Packages we added in our project can also be dependent on other dependencies and those can further have more dependencies and so on. This is not a problem for a website where you does not care about space and performance of application . It tells you need to care about dependency conflicts as all your dependencies use their own version of Underscore.This increases size and make heavy load for pages. Imagine a site having to download three copies of jQuery as due to different packages require different version of jquery

The reason many projects use both is that they use Bower for front-end packages and npm for developer tools like Yeoman, Grunt, Gulp, JSHint, CoffeeScript, etc.

SEPARATE PACKAGE DEPENDENCY APPROACH
The main difference between npm and Bower is the approach for installing package dependencies. npm installs dependencies for each package separately, and as a result makes a big package dependency tree (node_modules/grunt/node_modules/glob/node_modules/...), where there could be several version of the same package. For client-side JavaScript this is unacceptable: you can't add two different version for jQuery or any other library to a page. With Bower each package is installed once (jQuery will always be in the bower_components/jquery folder, regardless of how many packages depend on it) and in the case of a dependency conflict, Bower simply won't install the package incompatible with one that's already installed.

Benefits of Html Helpers in Asp.Net MVC

So today i am going to give an overview on Html helpers in Asp.Net MVC . So first questions that stuck our mind are -

 What are Html helpers ?

 Why to use them instead of using simple Html coded controls

 What are their benefits in Asp.Net MVC

Html helpers are very much similar to Asp.Net web controls . But Html helpers are much more lightweight as compared to Asp.net Web forms Server controls . The similarity between server controls in Asp.net webforms and Html helpers in Asp.Net MVC are Viewstate . Means they both contain the ability to hold or update the data on postbacks using ViewStates for each controls .

Main  Benefits Of using Html Helpers in Asp.net MVC

• MVC Html Helpers contains Overloaded Methods like IPostBackDataHandler that Pre-populate the values of html helpers means it works similar to as viewstates
• Html Helpers is also having one more advantage It provide inbuilt Validation for html helpers textboxes 

Available HTML Helpers 

There following HTML helpers can be used to render (modify and output) HTML form elements:

1. BeginForm()
2. EndForm()
3. TextArea()
4. TextBox()
5. CheckBox()
6. RadioButton()
7. ListBox()
8. DropDownList()
9. Hidden()
10. Password()

Sample Code To Demonstrate Use of Html Helpers

ASPX CODE

<%= Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.") %>

<% using (Html.BeginForm()){%>

<p>

<label for="FullName">FullName</label>

<%= Html.TextBox("FullName") %>

<%= Html.ValidationMessage("FullName", "*") %>

</p>

<p>

<label for="Username">Username</label>

<%= Html.TextBox("Username") %>

<%= Html.ValidationMessage("Username", "*") %>

</p>

<p>

<label for="Password">Password:</label>

<%= Html.Password("Password") %>

<%= Html.ValidationMessage("Password", "*") %>

</p>

<p>

<label for="Password">Confirm Password:</label>

<%= Html.Password("ConfirmPassword") %>

<%= Html.ValidationMessage("ConfirmPassword", "*") %>

</p>

<p>

<%= Html.CheckBox("ReceiveNewsletter") %>

<label for="ReceiveNewsletter" style="display:inline">Receive Newsletter?</label>

</p>

<p>

<input type="submit" value="Register" />

</p>

<%}%>

RAZOR CODE

@Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.")

@using (Html.BeginForm()){ 

<p>

<label for="FullName">FullName</label>

@Html.TextBox("FullName")  

@Html.ValidationMessage("FullName", "*")  

</p>

<p>

<label for="Username">Username</label>

@Html.TextBox("Username")  

@Html.ValidationMessage("Username", "*")  

</p>

<p>

<label for="Password">Password:</label>

@Html.Password("Password")  

@Html.ValidationMessage("Password", "*")  

</p>

<p>

<label for="Password">Confirm Password:</label>

@Html.Password("ConfirmPassword")  

@Html.ValidationMessage("ConfirmPassword", "*")  

</p>

<p>

@Html.CheckBox("ReceiveNewsletter")  

<label for="ReceiveNewsletter" style="display:inline">Receive Newsletter?</label>

</p>

<p>

<input type="submit" value="Register" />

</p>

} 

Advantage of Asp.Net MVC

Asp.net  is a part of .net platform for creating,building, deploying and running web applications using C#,VB etc .we can develop a web application by using Asp.Net Web Form and Asp.Net MVC. Asp.Net MVC is advanced technology that is most widely used nowadays . MVC is a great thing available for developers that makes work of developers easy and more flexible .

MVC stands for Model-View-Controller . MVC separates the code in 3 different things that make the code cleaner , flexible and easy to understand and modify . So Today I am going to tell some of big advantages or some good things that Asp.Net MVC provides as compared to Web-forms . This is not a comparison of Web-forms and MVC this is just overview or advantages or features that Asp.Net mvc provides us

1. Rapid Application Development ( RAD ) :- So first I will start with biggest advantage of Asp.net Mvc and this is the thing that is most in demand in Enterprises and everywhere in development area . This is Rapid application development . Asp.Net MVC provides Database First Approach for developing WebApplications . This approach is used with Scanfolding Technique this technique is like a magic provided in Asp.Net MVC . Scanfolding technique tells if you have designed your database in good manner that means if you have Created Normalized Database with all like Primary keys, foreign keys ,One-many , many-many relationships then you need not to do more effort for developing rest on your application in Asp.Net MVC Rest of things will be created with less efforts using scanfolding . With Asp.Net MVC you can have your simple basic website ready within 1 minute after you created your Database . So that was explanation to RAD in Asp.Net MVC

In Pic below we are choosing MVC5 scanfolding template


Then it automatically generate code for us

2. Partial Layouts :- In Asp.Net we ofter use User controls that were used for code reusability we create a user control then where we require that type of code that we coded in user control we call that user control there . In similar way Partial Layouts is provided in Asp.Net MVC .Partial Layouts are very useful things provided in Asp.Net MVC . Partial Layouts are like Master Pages that we use in Asp.Net web-forms . These are used as master pages or master layouts that can be called in any view in Asp.Net MVC . Like in php we use include ( "partialheader.php" ); to include some header in all pages or some specific pages so instead of writting that code in all pages we call then there . Similar in Asp.Net Web-Forms We use content placeholders and contentplaceholders are placed in Master Pages and when we call these master pages and use then in child forms then code of child forms is placed in content placeholder area In the similar way Partial layout works . The partial layout contains @Renderbody in Razor view then replace the child page or code of  page that is calling it

3. MVC Is  Stateless : Asp.Net was Statefull by using viewstates or sessions but Asp.net MVC is stateless . It will be wrong to say mvc is stateless it would say http is stateless . By stateless i mean there is nothing in http that holds the user session or that record the activity of user when user logged in etc so this was maintained or state was maintained using viewstate and sessions . This was used in asp.net Webforms because they contain server controls that contains viewstate and that postback the values and update viewstates But there is not server controls in Asp.Net MVC So it does not maintain states . It has divided the code in three patterns model-view-controller that handles everything That's why it says MVC is stateless But in actual http is stateless that why MVC is stateless

4. No Events : As we came to know there are no server controls in Asp.Net MVC so there are no events for any control as there are not server controls All this is handled by connection of controllers with views where views hold your html code or designing code and controller hold your logics code .

Difference Between ViewState and Session in Asp.Net

"View State and Session "
  The Two main State Management things used in Asp.net Web applications . We cannot even think of an application without ViewState and Session . So today i decided to gave an overview of what is the difference between viewstate and session why these two terms exist and what are their usage To clearify this difference i am giving some points below

1. So First of all what is a Session ? -- A Session is a Time or a span of time upto which user used that webapplication or for how much session of how much period of time user has used your webapplication will be called session . Session contains some values that will be used throughout the user interaction with the webapplication and used in more than one webpage that user navigate So we can say that it is a variable in simple sense that takes our value from one page to another and Session got distroyed or killed automatically after a particular span or time or it is automatically destroyed or cleared when like user signout of application or when user close the browser

A live example would be a web application where a user login . Each user that logs into your system will have a unique session. We can hold additional data into the session which can be used as the user browses your site. We can hold the username, userrole, userpermissions simply by adding it to the session:


Session[“userrole”] = “programmer”; 
Session[“username”] = “Ageek”; 

Session[“userpermissions"] = “cangotohell”; 

A Session  stores the information on the server side  . It stores the values or it uses server memory for storage of data that it holds in . Session variables will use different new and unique session variables for each different user that logs in to web application . large amount of data can be stored on the session, web sites that have a large amount of traffic not use this method, because it will put a severe load on the server memory.

2. Now What is ViewState ? -- so we are clear with session now comes the turn of viewstate . So ViewState is also used for holding our important data But in case of viewstate data is kept in the single viewstate page . It means viewstate data is not taken from one page to another page in this point it is different from session . 

ViewState is only used to Track to analyse the changes that occur to current page during postbacks of data to pages .The viewstate of page can be viewed if you right click on webpage and then clickon view page source then you will see some code of lines similar to below code --

<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value=””></input>

If you are having large number of viewstate fields then it will make the postbacks very slow as all viewstate values will be needed to updated during postbacks so it will make the webpage open slower

Data can be written into viewstate like we do in sessions . But it can retain that data only with life cycle of page after that it will be changed or updated .If you closes that page or redirects to another page then viewstate data will be reset .

How to fill data in viewstate and how to access that data 

ViewState[“PreviousPage”] = “http://www.google.com”; 

Retrieving data form ViewState:

string PreviousPage = ViewState[“PreviousPage”].ToString();  

Difference Between C programming and C++ programming Language

DIFFERENCE BETWEEN PROCEDURAL AND OBJECT ORIENTED PROGRAMMING

1.         C Follows Procedural Programming Approach . It is also called 
Structured programming approach. In Structured programming approach 
the program has well defined structure