CHAR Vs VARCHAR In Mysql

CHAR datatype used when you know the exact length of the value, ex: US Zipcodes (CHAR(7)), Mobile phone numbers (10 numbers only CHAR(10)) etc., And its length should be 0 to 255

VARCHAR datatype used in variable length inputs. Ex; User_firstname (VARCHAR(20)), street_address(VARCHAR(100)) etc.,
Its length should be 0 to 255 before Mysql 5.0.3 version, After 5.3.0 and later versions it should be 0 to 65,535.

See the example below:

Value CHAR(4) Storage Required VARCHAR(4) Storage Required
'' ' ' 4 bytes '' 1 byte
'ab' 'ab ' 4 bytes 'ab' 3 bytes
'abcd' 'abcd' 4 bytes 'abcd' 5 bytes
'abcdefgh' 'abcd' 4 bytes 'abcd' 5 bytes

Website optimization

Hi Friends,
Below urls are very useful for website optimization techniques.

http://www.fiftyfoureleven.com/weblog/web-development/css/css-sprites-images-optimization
http://www.peachpit.com/articles/article.aspx?p=447210
http://www.die.net/musings/page_load_time/
http://www.webdevelopment2.com/easily-increase-page-load-time-10-fold-jquery/

CSS Sprites -

If your web page had lot of images and it will take more time to load all images then you should use one technique called "CSS Sprites" which will load all your common UI images in one request so that your page loads much faster than ever before.

Another technique is place the below tag in head section of your page

Use Firebug and Yslow plugins for Firefox to know the performancd of the page load

Use Firebug for Firefox from a realistic net connection to see a graphical timeline of what it is doing during a page load. This shows where Firefox has to wait for one HTTP request to complete before starting the next one and how page load time increases with each object loaded. YSlow extends Firebug to offer tips on how to improve your site's performance

Access the website with ip address and username instead of doman name when dns was not propagated correctly

After uploded files to hosting server, you need to set the dns to access files with domain name, if you didn't set the dns, you can also call the application as below.

http://ip-address/~username/gallery/ OR http://ip-address/username/gallery/
Ex: http://192.168.12.10/~venkat/gallery/

Free SVN account from Google

Here are some very quick notes on getting a google svn hosting account set up with eclipse; as google is offering us all such an amazing resource, I have a feeling I'll be doing this again some time whilst working on other projects...

If you already have a gmail account, make sure you're logged in (that way, your repository and your account will be linked).

Start here:
http://code.google.com/hosting/
Go to the 'Create a new Project' link and create your project...

Install eclipse if you haven't already (current recent version is 3.5):
http://www.eclipse.org/downloads/

Now you need to install the subclipse plugin from within eclipse..
Here are some step-by-step instructions:
http://subclipse.tigris.org/install.html

Once that's done you should be able to open your repository as a new project within eclipse.

Within the package explorer (the panel on the left if you're in the java developer perspective), right click to get the context menu and go to 'New' and 'Other...'

expand the SVN folder and select 'Checkout Projects from SVN' and select Next

Select the Create a new repository location and select Next

The URL will be:

https://[YOUR_PROJECT_NAME].googlecode.com/svn

If you don't use https:// you'll check out the repository as read only

Select (highlight) the folder to check out as an eclipse project (e.g. trunk) and select Next.

Select the check out as a project configured using the New Project Wizard and select 'Finish'

For this exercise, I'm checking mine out as a java project, so I'm selecting Java Project and Next on the wizard box.

Give the Project a name (e.g. myProject), select Finish and OK

Let it check out your project...

You should see something like myProject [trunk] in the package explorer.
You can now right click on the folder and go to New > Folder and create a new folder

When you're ready, right click on the folder you've created, go to the Team context menu and select 'Add to Version Control'; you'll probably need to do this for any new files you subsequently add...

From then, commit will add new changes and update will refresh a stale repository.

One other note: to check out the project, I used my gmail username. The svn password isn't the same as your gmail password though.

I found the password for the code repository (when logged in) here - so hopefully this will help:

http://code.google.com/hosting/settings

NB: I've seen situations where subclipse (or subversion) would keep asking for a password; I managed to stop it from doing this by going into the Eclipse > Window > Preferences, expanding the Team folder, selecting SVN and ensuring that the SVN interface was selection was set to SVNKit (Pure Java).

Free SVN account from Google

Ok - here are some very quick notes on getting a google svn hosting account set up with eclipse; as google is offering us all such an amazing resource, I have a feeling I'll be doing this again some time whilst working on other projects...

If you already have a gmail account, make sure you're logged in (that way, your repository and your account will be linked).

Start here:
http://code.google.com/hosting/
Go to the 'Create a new Project' link and create your project...

Install eclipse if you haven't already (current recent version is 3.5):
http://www.eclipse.org/downloads/

Now you need to install the subclipse plugin from within eclipse..
Here are some step-by-step instructions:
http://subclipse.tigris.org/install.html

Once that's done you should be able to open your repository as a new project within eclipse.

Within the package explorer (the panel on the left if you're in the java developer perspective), right click to get the context menu and go to 'New' and 'Other...'

expand the SVN folder and select 'Checkout Projects from SVN' and select Next

Select the Create a new repository location and select Next

The URL will be:

https://[YOUR_PROJECT_NAME].googlecode.com/svn

If you don't use https:// you'll check out the repository as read only

Select (highlight) the folder to check out as an eclipse project (e.g. trunk) and select Next.

Select the check out as a project configured using the New Project Wizard and select 'Finish'

For this exercise, I'm checking mine out as a java project, so I'm selecting Java Project and Next on the wizard box.

Give the Project a name (e.g. myProject), select Finish and OK

Let it check out your project...

You should see something like myProject [trunk] in the package explorer.
You can now right click on the folder and go to New > Folder and create a new folder

When you're ready, right click on the folder you've created, go to the Team context menu and select 'Add to Version Control'; you'll probably need to do this for any new files you subsequently add...

From then, commit will add new changes and update will refresh a stale repository.

One other note: to check out the project, I used my gmail username. The svn password isn't the same as your gmail password though.

I found the password for the code repository (when logged in) here - so hopefully this will help:

http://code.google.com/hosting/settings

NB: I've seen situations where subclipse (or subversion) would keep asking for a password; I managed to stop it from doing this by going into the Eclipse > Window > Preferences, expanding the Team folder, selecting SVN and ensuring that the SVN interface was selection was set to SVNKit (Pure Java).

You can find more information regarding this from http://blog.msbbc.co.uk/2007/06/using-googles-free-svn-repository-with.html

Multi line CSS

Single line css

#wrapper {
width:800px;
margin:0 auto;
}

#header {
height:100px;
position:relative;
}

#feature .post {
width:490px;
float:left;
}

Multiline css
#wrapper {width:800px; margin:0 auto;}
#header {height:100px; position:relative;}
#feature .post {width:490px; float:left;}

If you use, Multiline css then you can easily find the style for an element when ever you need to customise it also the number of lines per style sheet would be decreased.

Backup database using php code

Hello Frineds,
Below code would take entire database backup and store it in the current folder. You can run this script automatically using crop job, so that you would have your database backup for every day or every week as you wish.

//backup_tables('localhost','root','rot','database_name','table_name'); //To backup one specific table
backup_tables('localhost','root','rot','database_name'); // To backup entire database
/* backup the db OR just a table */
function backup_tables($host,$user,$pass,$name,$tables = '*')
{

$link = mysql_connect($host,$user,$pass);
mysql_select_db($name,$link);

//get all of the tables
if($tables == '*')
{
$tables = array();
$result = mysql_query('SHOW TABLES');
while($row = mysql_fetch_row($result))
{
$tables[] = $row[0];
}
}
else
{
$tables = is_array($tables) ? $tables : explode(',',$tables);
}

//cycle through
foreach($tables as $table)
{
$result = mysql_query('SELECT * FROM '.$table);
$num_fields = mysql_num_fields($result);

$return.= 'DROP TABLE '.$table.';';
$row2 = mysql_fetch_row(mysql_query('SHOW CREATE TABLE '.$table));
$return.= "\n\n".$row2[1].";\n\n";

for ($i = 0; $i < $num_fields; $i++)
{
while($row = mysql_fetch_row($result))
{
$return.= 'INSERT INTO '.$table.' VALUES(';
for($j=0; $j<$num_fields; $j++)
{
$row[$j] = addslashes($row[$j]);
$row[$j] = ereg_replace("\n","\\n",$row[$j]);
if (isset($row[$j])) { $return.= '"'.$row[$j].'"' ; } else { $return.= '""'; }
if ($j<($num_fields-1)) { $return.= ','; }
}
$return.= ");\n";
}
}
$return.="\n\n\n";
}

//save file
$handle = fopen('db-backup-'.time().'-'.(md5(implode(',',$tables))).'.sql','w+');
fwrite($handle,$return);
fclose($handle);
}
?>

Difference between echo & return statements in function

Hi,
Here is the explanation about where we should use echo and where we should use return statements while working with functions.

If you want to print some thing on browser and continue execution of the process then you have to use echo statement.
Ex:

Recursive functions with static variables

function test()
{
static $count = 0;

$count++;
echo $count;
if ($count < 10) {
test();
}
$count--;
}
test();
?>
Here static variable is initialised only once when first called the test function and then it will maintain the value of $count till the end of the process.
O/P:12345678910

When you use the return statement the program execution stopped in that line and output some thing to the variable. So Calling return in your script or function will either end the script or end the function and then return the value
Ex:
function test($arg)
{
if ( $arg == 'ban' ) {
return 'Banana';
}
else
{
// There's nothing else to do, so end execution of this function
return;
}
}
$fruit = test('banana');
if ($fruit=='Banana')
{
echo 'Banana';
}
?>

PHP start session only once to prevent warnings

session_id() returns an empty string if there is no current session, so to test if a session already exists, its better to write this :

if(session_id() == "")
{
session_start();
}
else
{
// Anything you want
}

Get current page URL along with SSL protocal and port number In PHP

Hi, Below code will get the current page URL along with SSL protocal and port number

function curPageURL() {
$pageURL = 'http';
if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
$pageURL .= "://";
if ($_SERVER["SERVER_PORT"] != "80") {
$pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
} else {
$pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
}
return $pageURL;
}
?>
echo curPageURL();
?>

Search features in eclipse editor

Simple search and replace
Ctrl + F

Advanced search and replace
Ctrl + H

When you press Ctrl + H then search window will open in eclipse editor

Containing text: which text do you want to find. Ex: if you don't know some function was defined, then simply you can search for function funname(

File name patterns
*.php will search in all php files
*.* will search win all files

Scope
Workspace OR Enclosing Projects
Workspace means search in all projects
Enclosing Projects means search in current working project

Phonegap - an opensource framework for developing iphone and other applications

Phonegap is an open source framework for developing different mobile applications. By using HTML, CSS and Javascript we can create appliations with core features of iPhone, Ipad, Android, Palm, Symbian, Blackberry etc.,,

Sample code
http://github.com/sintaxi/phonegap

Official website
http://www.phonegap.com/

Open new tab in browser using js

//open new tab with blank address
window.open('', '_blank', 'toolbar=0,location=0,menubar=0');

//open new tab with url
window.open('http://www.google.com', '_blank', 'toolbar=0,location=0,menubar=0');

Wordpress plugin development

Hi Friends,

Here is very good information provided for wp plugin developement, it explained in a very easy way.

http://www.problogdesign.com/wordpress/a-novice-guide-to-wordpress-plugin-development/

Visual way to provide feedback and ask your employee to do necessary changes

Visual way to provide feedback and ask your employee to do necessary changes either on design or content of the webpage. To get started sign up at http://www.notableapp.com/

Jquery selectors reference for beginners

Hi Friends,

Jquery selectors are used to apply effects for all elements or some or group of elements by using classes or IDs and tag names.

Ex: $(‘#id’); This selector selects an element with the given ID.
$(‘.class’) The class selector will gather all elements in the document with the given class name
:first $(‘ul li:first’); Returns the first element in a result set


You can see the complete information at below url.
http://www.pamaya.com/jquery-selectors-and-attribute-selectors-reference-and-examples/

Tricky interview questions revealed by yahoo

When it comes to appearing for a job interview, we all prepare ourselves by finding out about our potential employers, but at times we are asked an off-the-wall question that leaves us stumped.

In order to help us prepare for such questions, Glassdoor.com, a two-year-old Sausalito, Calif. website that bills itself as "the TripAdvisor for careers", compiled a list of some of the top oddball interview questions.

Glassdoor gets its information directly from employees who work at 84,000 companies, reports ABC News.

According to Rusty Rueff, a consultant at Glassdoor, who is the author of Talent Force: A New Manifesto for the Human Side of Business and former head of human resources said ninety percent of people don't know how to deal with them.

Rueff advises, first you have to realize that the interviewer isn't trying to make you look stupid, as stupid as the question may seem.

With a question like "How many hair salons are there in Japan", the interviewer is giving you an opportunity to demonstrate your thought processes.

Rueff says you should think out loud, like the contestants on Who Wants to be a Millionaire? You might start by saying, we'd have to know the population of Japan, and then we'd have to figure out what percentage of them get their hair done and how often.

Rueff says it's fine to pull out a pen and paper and start doing some calculations right there in the interview.nother example, which may seem equally impossible to answer: Why are manhole covers round?

Just start thinking through the question, out loud, Connie Thanasoulis-Cerrachio, a career services consultant at Vault.com advises.

"I would say, a round manhole cover could keep the framework of the tunnel stronger, because a round frame is much stronger than a square frame," she suggested.

Other weird-seeming questions, like "If you were a brick in a wall, which brick would you be and why," or "If you could be any animal, what would you be and why," are really just invitations to show a side of your personality.

Thanasoulis-Cerrachio says a friend who is chief executive of a market research company used to ask applicants what kind of car they would be.

"She wanted someone fast, who thought quickly. She wanted someone who wanted to be a Maserati, not a Bentley," Thanasoulis-Cerrachio said.

For the brick question, Thanasoulis-Cerrachio advises saying something like, "I would want to be a foundational brick because I'm a solid person. You can build on my experience and I will never let you down." (ANI)

Move Wordpress to another host

Simple process to get work.

Wordpress application run in another host or another url.

Wordpress will configure all the paths in database only, ex: when you upload any image, its absolute path stored in database. And all content will reside in wp-content folder.

New host
1. First install new wordpress in new host

Old host
2. Take mysql backup from old site. or goto Tools -> Import in wp-admin.
This should be used later for running old application

Old host
3.
Login admin panel of old site, Goto settings -> General
change WordPress address (URL) and Blog address (URL) against new host and click "Save Changes"
Now the database will updated with new host urls.

4. Old host
Goto phpmyadmin and export the database or goto Tools -> Export in wp-admin.

5. Old host
Revert back the database with old one, i.e we took backup on step-2.

New host
6. Import the old application's database which we get from step 4.

New host
7. Copy the wp-content folder from old host and pasted it into new host.

Now, upon completion of these steps we can sucessfully run the same application in both the hosts.

( OR )

You can copy all the files from old server and pasted it in new server and follow below process.

wp-config.php is the main configuration file for database connections and others.

Edit wp-config.php file to suit with your database
//DB_USER etc.,

Open database goto wp_options table and change the below two rows

option_value='your-new-url' where option_name='site url' and
option_value='your-new-url' where option_name='home'.

If you didn't change this siteurl value in this table your site will connect to old site when you try to access admin panel.

After done, goto /wp-admin section through browser and enter admin details.
Then goto Settings -> General -> change urls.
Now site configured and worked properly in new server or localhost.

In database replace every occurance of http://oldserver/wp-content links with http://newserver/wp-content. So that image links are worked currectly.

Some settings are fixed in wp-settings.php file.


Complete Reference

http://www.dollarshower.com/move-wordpress-blog-to-another-host-server/

http://support.hostgator.com/articles/pre-sales-questions/how-to-transfer-your-wordpress-blog-from-one-host-to-another-host

http://www.makeuseof.com/tag/move-wordpress-blog-host/







Custom fields in wordpress
http://codex.wordpress.org/Using_Custom_Fields