Sunday, 9 February 2014

jQuery Installation

jQuery Installation:

Adding jQuery to Your Web Pages

There are several ways to start using jQuery on your web site. You can:

Download the jQuery library from jQuery.com

Include jQuery from a CDN, like Google

Downloading jQuery

There are two versions of jQuery available for downloading:

Production version

Development version

Steps needs to follow:

1. Open your favorite browser and point it to this address: http://www.jquery.com

2. Find the section labeled “Grab the Latest Version!” Then, select the checkbox next to “Production.”.

3. Click the “Download jQuery” button.

4. The next page you’ll see will look something like this. Save the page into a folder called scripts on your drive

See figure:

What’s the difference between the Production and Development versions?

The Production version of jQuery is a minified version, intended for speed of execution on a web server.

The Development version is intended for developers interested in exploring and extending the inner workings of thejQuery library.

How to use downloaded jQuery library?

The jQuery library is a single JavaScript file, and you reference it with the HTML <script> tag (notice that the <script> tag should be inside the <head> section):

Do you wonder why we do not have type="text/javascript" inside the <script> tag?

This is not required in HTML5. JavaScript is the default scripting language in HTML5 and in all modern browsers!

Alternatives to Downloading

If you don't want to download and host jQuery, you can include it from a CDN (Content Delivery Network). Both Google and Microsoft host jQuery.

To use jQuery from Google or Microsoft, use one of the following:

Google CDN:

Microsoft CDN:

One big advantage of using the hosted jQuery from Google or Microsoft
Many users already have downloaded jQuery from Google or Microsoft when visiting another site. As a result, it will be loaded from cache when they visit your site, which leads to faster loading time. Also, most CDN's will make sure that once a user requests a file from it, it will be served from the server closest to them, which also leads to faster loading time.

Components of Browser

Browser layout engine - The browser’s layout engine goes through the HTML and CSS to build a “document” using the HTML Document Object Model (DOM).

Browser viewport - The browser displays a rendered page in thebrowser’s viewport.

JS interpreter - The JS interpreter references the DOM to make changes to the web page without needing to reload it.

How web pages works?

1. The browser requests a web page from a server when someone types a web address into the browser’s URL bar.

2. The server finds the requested file(s) and sends them to the browser

3. The browser displays a rendered HTML page based on the file sent from the server.

The power of script

To change your web pages on the fly, with an HTML tag known as <script>

Role of jQuery (and JavaScript)

Every browser comes with a built-in JavaScript interpreter that takes the directions you write in between the <script>tags and translates those directions into different kinds of action on the web page.

jQuery is a JavaScript library specialized for changing web page documents on the fly.

What is JavaScript?

JavaScript is a scripting language that was designed for use within a web browser. Typically, JavaScript is used for interface interactions. Slideshows and other interactive components are typically done using JavaScript.

What is jQuery?

jQuery is a lightweight, "write less, do more", JavaScript library.

jQuery is an open source, cross-browser, CSS3 compliant JavaScript library that has made client side scripting relatively easier. It can produce dynamic web pages as well as Flash-like animations. jQuery today powers over 55% of the 10,000 most visited websites on the internet.

jQuery also simplifies a lot of the complicated things from JavaScript, like AJAX calls and DOM manipulation.

The jQuery library contains the following features:

HTML/DOM manipulation

CSS manipulation

HTML event methods

Effects and animations

AJAX

Utilities

Why jQuery?

It comes with MIT License (http://opensource.org/licenses/MIT) and is open source.
Cross-browser Compatibility
Fast & Small Footprint
Short Learning curve & Great Documentation (http://docs.jquery.com)
Tons of Plugins and Helpful Utilities(jQuery UI)
CSS3 Selectors Compliant
Widespread Adoption
Bugs free or fixed pretty quick

Source: Top-8-reasons-why-jquery-is-so-popular.aspx

Why not jQuery?

jQuery is easy to accomplish, but not always easy to implement as compared to, say, CSS.

Even though it is swift, the end product may not always be fast-paced.

You just have to get the version correct, and pray that you keep getting it correct.

If improperly used as a framework, things can get complicated beyond measure.

Useful MySQL Database Commands

Create a database on the sql server.

mysql> create database
[databasename]; 

List all databases on the sql server.

mysql> show databases;

Switch to a database.

mysql> use [db name];

To see all the tables in the db.

mysql> show tables;

To see database's field formats.

mysql> describe [table name];

To delete a db.

mysql> drop database [database
name]; 

To delete a table.

mysql> drop table [table name];

Show all data in a table.

mysql> SELECT * FROM [table
name]; 

Returns the columns and column information pertaining to the designated table.

mysql> show columns from [table
name]; 

Show certain selected rows with the value "whatever".

mysql> SELECT * FROM [table name]
WHERE [field name] = "whatever"; 

Show all records containing the name "Bob" AND the phone number '3444444'.

mysql> SELECT * FROM [table name]
WHERE name = "Bob" AND phone_number = '3444444'; 

Show all records not containing the name "Bob" AND the phone number '3444444' order by the phone_number field.

mysql> SELECT * FROM [table name]
WHERE name != "Bob" AND phone_number = '3444444' order by
phone_number; 

Show all records starting with the letters 'bob' AND the phone number '3444444'.

mysql> SELECT * FROM [table name]
WHERE name like "Bob%" AND phone_number = '3444444'; 

Show all records starting with the letters 'bob' AND the phone number '3444444' limit to records 1 through 5.

mysql> SELECT * FROM [table name]
WHERE name like "Bob%" AND phone_number = '3444444' limit 1,5; 

Use a regular expression to find records. Use "REGEXP BINARY" to force case-sensitivity. This finds any record beginning with a.

mysql> SELECT * FROM [table name]
WHERE rec RLIKE "^a"; 

Show unique records.

mysql> SELECT DISTINCT [column
name] FROM [table name]; 

Show selected records sorted in an ascending (asc) or descending (desc).

mysql> SELECT [col1],[col2] FROM
[table name] ORDER BY [col2] DESC; 

Return number of rows.

mysql> SELECT COUNT(*) FROM
[table name]; 

Sum column.

mysql> SELECT SUM(*) FROM [table
name]; 

Join tables on common columns.

mysql> select
lookup.illustrationid, lookup.personid,person.birthday from lookup left join
person on lookup.personid=person.personid=statement to join birthday in person
table with primary illustration id; 

Create a new user. Login as root. Switch to the MySQL db. Make the user. Update privs.

# mysql -u root -p mysql> use
mysql; mysql> INSERT INTO user (Host,User,Password)
VALUES('%','username',PASSWORD('password')); mysql> flush privileges; 

Change user’s password from unix shell.

# [mysql dir]/bin/mysqladmin -u
username -h hostname.blah.org -p password 'new-password' 

Change user’s password from MySQL prompt. Login as root. Set the password. Update privs.

# mysql -u root -p mysql> SET
PASSWORD FOR 'user'@'hostname' = PASSWORD('passwordhere'); mysql> flush
privileges; 

Recover a MySQL root password. Stop the MySQL server process. Start again with no grant tables. Login to MySQL as root. Set new password. Exit MySQL and restart MySQL server.

# /etc/init.d/mysql stop #
mysqld_safe --skip-grant-tables & # mysql -u root mysql> use mysql;
mysql> update user set password=PASSWORD("newrootpassword") where
User='root'; mysql> flush privileges; mysql> quit # /etc/init.d/mysql
stop # /etc/init.d/mysql start 

Delete a column.

mysql> alter table [table name]
drop column [column name]; 

Add a new column to db.

mysql> alter table [table name]
add column [new column name] varchar (20); 

Change column name.

mysql> alter table [table name]
change [old column name] [new column name] varchar (50); 

Make a unique column so you get no dupes.

mysql> alter table [table name]
add unique ([column name]); 

Make a column bigger.

mysql> alter table [table name]
modify [column name] VARCHAR(3); 

Delete unique from table.

mysql> alter table [table name]
drop index [colmn name]; 

Load a CSV file into a table.

mysql> LOAD DATA INFILE
'/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ','
LINES TERMINATED BY '\n' (field1,field2,field3); 

Dump all databases for backup. Backup file is sql commands to recreate all db's.

# [mysql dir]/bin/mysqldump -u root
-ppassword --opt >/tmp/alldatabases.sql 

Dump one database for backup.

# [mysql dir]/bin/mysqldump -u
username -ppassword --databases databasename >/tmp/databasename.sql 

Dump a table from a database.

# [mysql dir]/bin/mysqldump -c -u
username -ppassword databasename tablename > /tmp/databasename.tablename.sql

Restore database (or database table) from backup.

# [mysql dir]/bin/mysql -u username
-ppassword databasename < /tmp/databasename.sql 

Create Table Example 1.

mysql> CREATE TABLE [table name]
(firstname VARCHAR(20), middleinitial VARCHAR(3), lastname VARCHAR(35),suffix
VARCHAR(3),officeid VARCHAR(10),userid VARCHAR(15),username VARCHAR(8),email
VARCHAR(35),phone VARCHAR(25), groups VARCHAR(15),datestamp DATE,timestamp
time,pgpemail VARCHAR(255)); 

Create Table Example 2.

mysql> create table [table name]
(personid int(50) not null auto_increment primary key,firstname varchar(35),middlename
varchar(50),lastnamevarchar(50) default 'bato'); 

Dynamically add button, textbox, input, radio elements in html form using JavaScript

Adding Elements like textbox, button, radio button etc in a html form using JavaScript is very simple. JavaScript’s document object has a method called createElement() which can be used to create html elements dynamically.
We had used this function in our tutorial: Dynamic combobox-listbox-drop-down using javascript to add dynamic options to a combo box-listbox. Let us use this function to create textboxes, radio buttons, buttons etc dynamically and add them in our page.

Following is the source code of our example.

<HTML>

<HEAD>

<TITLE>Dynamically add Textbox, Radio, Button in html Form using JavaScript</TITLE>

<SCRIPT language="javascript">

function add(type) {

    //Create an input type dynamically.

    var element = document.createElement("input");

    //Assign different attributes to the element.

    element.setAttribute("type", type);

    element.setAttribute("value", type);

    element.setAttribute("name", type);

    var foo = document.getElementById("fooBar");

    //Append the element in page (in span).

    foo.appendChild(element);

}

</SCRIPT>

</HEAD>

<BODY>

<FORM>

<H2>Dynamically add element in form.</H2>

Select the element and hit Add to add it in form.

<BR/>

<SELECT name="element">

    <OPTION value="button">Button</OPTION>

    <OPTION value="text">Textbox</OPTION>

    <OPTION value="radio">Radio</OPTION>

</SELECT>

<INPUT type="button" value="Add" onclick="add(document.forms[0].element.value)"/>

<span id="fooBar">&nbsp;</span>

</FORM>

</BODY>

</HTML>

Also note that we have used setAttribute() method to assign the attributes to our dynamically created element.

Sample Text

Unordered List