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Wednesday, February 11, 2015

SQL Injection Attacks How to Prevent VB Net Database Applications

What is SQL Injection?

SQL injection is a code injection technique which is used to attack data-driven applications in which malicious SQL statements are inserted into an entry field for execution.

This VB.Net tutorial will guide you through the use of parameterized SQL queries and demonstrate how they can be used to prevent SQL injection attacks by your application users.

SQL Injection Attacks - How to Prevent VB.Net Database Applications

Also Read: How to Create a Keylogger in VB.Net?

Now the question comes in our mind that what is parameterized SQL queries? We will later on discuss about it in this tutorial.

Lets take a small example. As you know to insert some records in database we use the following query:

Insert into Table_Name Values(" & textbox1.text & "," & textbox2.text & "," & textbox3.text & ")

Now the problem in above code is that users can modify our query at runtime using SQL injection.

SQL Injection Attack Example

Lets take an example of a small SQL injection attack. Just forget the above query and assume that the query is:

Select * from Table_Name Where Username=" & TextBox1.Text & "

Now if the user inputs x OR x=x in TextBox1 then he can make the above query return true value and the result would be displaying all records starting with letter x.

How to Prevent SQL Injection Attacks

In order to avoid above problem we use parameterized SQL queries. Now lets take an example of parameterized query. Its very simple, we just need to add parameters instead of values.

Insert into Table_Name Values(@username,@password)

Note that parameters always starts with @ symbol. Now we need to assign values to these parameters in the following way.

Syntax: SQLCommand.AddParam("ParameterName", value)
Example: SQLCommand.AddParam("@username",TextBox1.text)

Using this method we can easily avoid SQL injections attacks. Below video contains a detailed guide about how to prevent SQL injection attacks.

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Difference between Native Web and Hybrid Mobile Applications

Title : Difference Between Native Web and hybrid Mobile Applications.

Hi, I am going to explain the main differences between Native , Web and Mobile Applications.In Present days smart phones are playing a major role in market where millions of people are expecting new features and new technologies in their mobiles.Every person using smart phone want to change his mobile in two years and expecting to purchase new mobile with more features then the previous mobile what he is using.
so that as a mobile developer we have to come with new technology with that we have to consider cost,portability,reusablity,performance,user interactivity and apperance.based upon the above things i am going to exaplain how native applications,web applications and hybrid applications play and which one to choose.

Native Apps : Native mobile Applications are the applications build using the native language of the mobile and can be deployed to a specified store for example if we want to build native android application we have to know java and using java and android sdk we can build native android app and can only be deployed android market(Play Store).where as iphone applications can be developed by a c++ proggramer
and can be only deployed itunes.coming to portability Native apps are platform dependent.coming to cost native apps are cost as we need different programmers for devloping different native apps and every application need to be deployed in its own market store and we have to pay for diploying our applications.
coparing to others native applications are fast , user interactive, provide good apperance and also deploying to market stores makes your application reachable to users easily.

to develop native applications please refer the following link.

Web Applications : Web Applications are simple applications build using HTML5 and JavaScript and can be deployed in our own webservers. any mobile user can use this application from their mobile browser.compared to native apps this applications are low cost and can be used by any mobile user it is platform independent.Compared to native apps web apps are slow,appearence is not good as native apps,we cannot use mobile hardware like camera,gps,sensors.any web developer can develop web apps and can deploy the apps in their own web server and can be accessed by any mobile os devices.

to devlop web apps please refer the following link.

Hybrid Apps : Hybrid Apps are the applications build using HTML5 And JavaScript and deployed to any mobile os store by just changing some configurations and this is done by some opensource frameworks like PhoneGap.PhoneGap is a frame work that consists of different libraries which can convert a web application into native application and uses native apps webview and display the webapp in the webview and makes work as native apps.it is platform independent(but need to change some configurations while deploying).
it solves many disadvantages seen in webapplications and native applications.cost is less then native apps,can be deployed in market stores like playstore,itunes,ovi.Mobile hardware can be accessed by hybrid apps as native apps uses.user interactivity is good any web developer can build this hybrid apps with some additional things.user interactivity is good,appearence is good,reusability.

to develop hybrid apps please refer the following link.