A data model is a description of the organization of data in a database. It also describes the relationship among data and any constraints that have to be defined on the data.
Data models can be broadly be classified into two categories:
Object-based logical model
It focuses on describing the data, the relationship among the data, and any constraints defined.
Record-base logical model
It focuses on describing the data structure and the access techniques in a Database Management System.
A database management system (DBMS) is a software used to store and manage data. A DBMS stores data in databases and uses data models to describe the various ways of organizing data.
Definition 2:
Database Management System is the task of maintaining databases so that information is readily available.
DBMS's are designed to maintain large volumes of data.Management of data involves:
Defining structures of data storage.
Providing mechanisms for data manipulation such as adding, editing, and deleting data.
Providing data security against unauthorized access.
A relational database management system (RDBMS) is an advanced version of DBMS that also defines the relationship between the various data values. It helps in organizing and accessing data more efficiently than DBMS.
Class is a declaration, a template, or a blueprint that can be used to classify objects.
For example, the peacock, the sparrow, and the kingfisher are all birds. All of them share characteristics that are common to the family of birds. All of them lay eggs, are covered with feathers, have hollow bone structures, and have the ability to fly. Therefore, they share structural and behavioral similarities and belong to the class called Birds.
An object is a combination of messages and data. Objects can receive and send messages and use messages to interact with each other. The messages contain information that is to be passed to the recipient object.
Definition 2:
An object literally means a 'material thing' that is capable of being presented to the senses.
Definition 3:
An object is a tangible entity that may exhibit some well-defined behavior. For example, let us consider a tennis ball:
A tennis ball is a tangible entity, with a visible boundary.
A tennis ball has a specific defined purpose (such as bouncing)
You can direct a specific action towards a tennis ball by hitting it with racquet or by tossing it.
Object-Oriented Programming (OOP) is one of the most popular methodologies in software development. It offers a powerful model for creating computer programs. It speeds the program development process, improves maintenance and enhances reusablity of programs.
jQuery is powerful client side scripting language. It is easy to learn language. It supports large number of browser which includes IE, Firefox, etc. It is JavaScript library of code that is already written by sine talented programmers. It simplifies most of the complex tasks that you don't need to worry. Below code display and hide Hello World!!! text using jQuery.
There are situations when you work with File Upload controls and you want to show the image preview when you hit ok in the dialog box. There are many solution but we are going to demonstrate using JavaScript. Now the below code snippet uses showImage function which first splits the complete path present in file upload text box. Later it appends 'file:///' to the complete file path.
Example:
function showImage(id,img,divName,no)
{
var fileUploader = id.value;
dots = fileUploader.split(".");
//get the part AFTER the LAST period.
fileType = "." + dots[dots.length-1];
if(fileType=='.jpg'||fileType=='.JPG'||fileType=='.gif'||fileType=='.GIF' ||fileType=='.jpeg'||fileType=='.JPEG'||fileType=='.bmp'||fileType=='.BMP'|| fileType=='.png'||fileType=='.PNG'||fileType=='.tif'||fileType=='.TIF'||fileType=='.thm'||fileType=='.THM')
{
// alert('That file is OK!');
// return true;
}
else
{
return false;
}
var filePath = fileUploader.split("\\");
var path = 'file:///';
for(var i = 1; i < filePath.length;i++)
{
path += filePath[i];
if(i != filePath.length -1)
path += "/";
}
if(path.length > 1)
{
if(no==1)
{
var ele= document.getElementById('<%= panellogo.ClientID %>');
ele.style.display = 'block';
var ele1= document.getElementById('<%= imglogo.ClientID %>');
}
else if(no==2)
{
var ele= document.getElementById('<%= panelheader.ClientID %>');
ele.style.display = 'block';
var ele1= document.getElementById('<%= imgheader.ClientID %>');
}
else if(no==3)
{
var ele= document.getElementById('<%= panelfooter.ClientID %>');
ele.style.display = 'block';
var ele1= document.getElementById('<%= imgfooter.ClientID %>');
}
else if(no==4)
{
var ele= document.getElementById('<%= panelmiddlebar.ClientID %>');
ele.style.display = 'block';
var ele1= document.getElementById('<%= imgmiddlebar.ClientID %>');
}
ele1.src =path ;
}
}
There are situations where you need to change value present in grid view dynamically. In one of my project, I need to calculate price according to the number of food items selected from a drop-down list control and this will be client site operation. To do that I have used JavaScript. Below is the ASP.NET and JavaScript which you need to past it in ASP.NET page.
