Json with ajax

Json with ajax

Is a web development technique for creating interactive web applications.

It is way to store information in an organized ,easy to access manner, it gives us human readable collection of data that we can access in a really logical manner.

Serialization

Is the process of taking an object and converting it to a format in which it can transported across a network.

Deserialization:

Is the process of using the serialized state information to reconstruct the object from the serialized state to its original state.

The json format is often used for serializing and transmitting structured data.

Ajax is a new technique for creating better, fast and more interactive web app, with the help of XML, html, css and JavaScript

                 

Ajax is used to increase the web page interactively speed and usability

Ajax is the technique of exchanging data with a server and updating the parts of web page without reloading the whole page

Ajax uses XHTML for content and css for presentation as well as the document object model (and javascript for dynamic content display)

Ajax is a web browser technology independent of web server software

Technologies used in Ajax

JavaScript:
It loads typed scripting language JavaScript function is called when an event in the page occurs for the whole Ajax operation

DOM:

API for accessing and manipulating structured documents

Represents the structure of XML and HTML documents

CSS:

Allows for a clear separation of the presentation style from the content and may be changed programmatically by JavaScript.

XMLHttpRequest

JavaScript function that performs asynchronous interaction with the server.

Jquery Ajax

Is a great tool or library which provides a rich set of Ajax Methods to develop interactive web applications

With the Jquery Ajax Methods we can request text, Html, XML or JSON from a remote Server using both HTTP Post or HTTP Get and we can load the external data directly into the selected Html element of our web page

Loading Data using Jquery Ajax

This is very easy to load any static or dynamic data using Jquery Ajax. In order to do this Jquery provides load() method.

Load method: load data from a server and puts the returned data into the selected html element.

Syntax:

[selected].load(url,[data],[callback]);

Data-optional

Callback-success

The required URL parameters specifies the URL that you wish to Load.

The optional data parameter specifies a set of query string key/value pairs to send along with the request.

The optional call back parameter is the name of the function to be executed after the load () method is completed.

Example:

Loading the data from the html page  or we can say loading html content dynamically using Ajax loads()

Page1.html

Page2.html

           

output

  

Loading the content of text file in jQuery ajax load method

TextFile.txt

Write any data

$(“divMain”).load (‘TextFile.txt’);

Passing Data to the Server

Many times we collect input from the user and then we pass that input to the server for further processing.

JQuery Ajax made it easy enough to pass collected data to the server using the Parameter of any available AJAX method

Ex Load ()

Example

Example:

Create two pages with the following names: HtmlPage1.htm and Default.aspx

HtmlPage1.htm

Default.aspx.cs

And run the page HtmlPage1.htm

And then click on Calculate Button the result should be displayed in Default Page

Loading the Data from the Database

LoadData.html

Default2.aspx.cs

Output:

GetMethod()

Jquery.get()

Loads the data from the server using a Http GetRequest

Jquery.Post()

Loads the data from the server

Example

htmlPage

GetServerDateTime.aspx

Output:

$(document).ready(function () {

        $("#btnDt").click(function() {

            $.post("GetServerDateTime.aspx",function(response) {

                alert(response);

            });

        });

        });

var employees = [
    {"firstName":"John", "lastName":"Doe"}, 
    {"firstName":"Anna", "lastName":"Smith"}, 
    {"firstName":"Peter", "lastName": "Jones"}
]

xml	json
more in size	less in size
developed by world wide consortoin	developed by douglos crockford
it has end tags	it does not has end tags

value type and reference type

What are Value types and Reference types?

Memory allocates within a compile time and it will use a stack memory. Stack is faster in access. Stack is under the control of os, so garbage collector can’t interact with this.

Stack is used to store small amount of data.

Reference type: memory allocates in run time and it will uses heap memory. DE allocation of the memory will be take care by garbage collector.

Garbage collector will destroy unused object in memory.

String & Object types comes under Reference Type.

========================================================

What is Implicitly Typed Variable?

This is a new feature, which allows you to declare a variable using the keyword var.

Ex: var x=100-> x is integer

Var s=”Hello”->s is string.

What are Null able Value Types?

To store Null Values we can store null values in value types also

Example:

String str =null ->valid

In value type:

int x=null   à invalid

int? x=null->valid

Normalization in database

Normalization

The process of minimizing data redundancy with a process of steps is called Normal Forms

 The total normalization process include 9 NF

First Normal Form

Second Normal Form

Third Normal Form

Boycee-Code Normal Form

Fourth Normal Form

Fifth Normal Form

Restrict Union Normal Form

Project Join Normal Form

Sixth Normal Form

First Normal Form

A table is said to be in first Normal Form, only when it has a primary key and it does not contain multiple valued columns

Example

The following table is created for storing the details of the customer of the company

Cust id	Name	Surname	Phone no
1001	Venkat	B	111111
1002	Sai	S	222222
1002	Sai	S	333333
1003	Rakesh	K	444444
1003	Rakesh	K	555555

The above table customer id  is the primary key, but the table is not in first normal form because it has a multi value column phone no

A customer may have multiple contact number hence, phone no column is a multi valued column to convert this table to first normal form divide it into two tables as follows

Cust id	Name	Surname
1001	Venkat	B
1002	Sai	S
1003	Rakesh	K

Cust id	Phone no
1001	111111
1002	222222
1002	333333
1003	444444
1003	555555

In, this table customer id, will be foreign key the above two table , the first table customer id is the primary key and in the second table customer id is the foreign key referring the customer id of the first table.

Second Normal Form

A table is said to be in second normal form, if and only if the table is in first normal form and second normal form and no partial dependencies exists in the table

When, a primary key is on combination  of multiple columns but if the non primary key column depends on part of the primary key and not on entire primary key, then the dependencies is called as partial dependencies

Example

To store the orders placed by the customers to a company the following table is created

order id	item	custname	order date
1	ram	c1	10/1/2007
1	hd	c1	10/1/2007
2	ram	c2	12/10/2007
2	motherboard	c2	12/10/2007

In, the above table primary key is on the combination of order id , item but now primary key columns customer name, order date depends only on order id and not on item, which is called as partial dependencies

Hence, the table is not in second normal form to convert the table to second normal form divide it into a tables as follows

order id	custname	orderdate
1	c1	10/10/2007
2	c2	12/102007

order id	item
1	I1
1	I2
2	I1
2	I5

The above two tables in the first table order id is the primary key, and in the second table order id is the foreign key

Third Normal Form

A table is said to be in the third normal form if and only the table is in second normal form and table does not contains transient dependencies when a non primary key column depends

Example

For storing the details of php students along with details of the professor guiding them a table is created as follows

studentid	s name	professor	prof phone
s1001	ravi	sunil	99999
s1002	srinivas	naresh	88888
s1003	kiran	chandu	343434343
s1004	fsas	dfsa	34343

               

The above table student id is primary key, but the non primary key column professor phone  depends on another non primary key column  professor, than  it is called as transient dependencies

Hence, the table is not in third normal form

To convert this table to third normal form divide it into two tables as follows

prof id	professor	prof phone
prof1	sunil	9999
prof2	naresh	9999
prof3	dsfs	3434343

student id	student name	prof id
s1001	ravi	prof1
s1002	srinivas	prof2
s1003	kiran	prof3
s1004	sfsf	prof2