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[PHP] Resources for programming with PDO

I’ve asked Twitter user what kind of PHP class would have used for a project and I was (and I am) in doubt between MDB2 (a PEAR Abstraction layer class) and mysqli extension. Someone has pointed out PDO, so I’m collecting some links to see what does this extension do:

• PDO on PHP web site: surely the first place to look at;
• Introduction to PDO on PHPPro: a big article which illustrates how to connect to different DBMS;
• Prepared statement with PDO
;
• Using PDO Objects in PHP 5, Handling Result Sets and More with PDO Objects in PHP 5 and Working with Prepared Queries with PDO Objects in PHP 5 all by Alejandro Gervasio;
• First steps with PDO;
• Fetching data with PDO;
• Developing MySQL Database Applications With PHP Part 3: Using the PDO Extension With MySQL Driver, pdo_mysql;
• PDO: The underestimated way to connect to your database;

[JS] How to get a querystring value given the key

Suppose you have an URL like this: www.host.com?m=5&lang=it. If you want to retrive the value of lang, you could simply use this function:

function parseURL(url,key)
{
  var reQS = new RegExp("[?&]"+key+"=([^&$]*)", "i");
  var offset = url.search(reQS);
  return ( offset >= 0 ) ? RegExp.$1 : null;
}

// usage
var myKey = parseURL("www.host.com?m=5&lang=it","lang")

[JS] How to get the time and unixtime

Self explanatory code:

var T = {
 getUnixTime: function() {
   return parseInt(new Date().getTime().toString().substring(0, 10));
 },
	
// format hh:mm:ss
getTime: function() 
{
  var d= new Date();
  var time = new Array();
  var hours = d.getHours();
  time.push(hours);
  var minutes = d.getMinutes().toString().length < 2 ? "0"+d.getMinutes() : d.getMinutes(); 
  time.push(minutes);
  var seconds = d.getSeconds().toString().length < 2 ? "0"+d.getSeconds() : d.getSeconds(); 
  time.push(seconds);
  	
  return time.join(":");
 }
}	

[JS] How to extend Array object to get the index of an its value

The code is self explanatory: you have an array and you want to know what index has the element “pippo” or “5”. So I extended the array object with prototype keyword to scan the array and to return the index if found, -1 otherwise.

var points = [56,12,36];

Array.prototype.getIndex = function(aVal) 
{
   for(item in this)
     if(aVal == this[item])
       return item;
   
   return -1;
}

console.log(points.getIndex(36));

[Bash] How much memory consume a process

ps -aylC geany |grep "geany" |awk '{print $8'} |sort -n |tail -n 1

[MySQL] Using information_schema instead of SHOW commands

PHP can handle data returned by SHOW commands, but information about all databases and tables are stored in information_schema database. Some useful queries:
1) Getting only columns name:

SELECT `column_name` 
FROM information_schema.columns
WHERE `table_name`="mytable";

SHOW columns 
FROM table 
WHERE field = "myfield"

select table_name as tables, engine,            
          table_rows as records, 
         auto_increment-1 as lastId  
FROM information_schema.tables  
WHERE table_name = "t5_user";

SELECT id 
FROM  MYDB.MYTABLE 
ORDER BY id DESC LIMIT 1

SELECT concat( table_schema, '.', table_name ) table_name, 
              concat( round( data_length / ( 1024 *1024 ) , 2 ) , 'M' ) data_length, 
              concat( round( index_length / ( 1024 *1024 ) , 2 ) , 'M' ) index_length, 
              concat( round( round( data_length + index_length,2 ) / ( 1024 *1024 ) , 2 ) , 'M' ) total_size 
FROM information_schema.TABLES 
HAVING data_length LIKE "___.%" 
OR data_length LIKE "____.%" 
ORDER BY data_length DESC ;

[jQuery] How to use Prototype or MooTools with jQuery

Since many libraries make use of the $ identifier, we need a way to prevent collisions between these names. jQuery provides a method called .noConflict() to return control of the $ identifier back to other libraries. Typical usage of .noConflict() follows the following pattern:

[jQuery] How to add a CSS class to external links

 // apply a class to all <a> which respect the filter selection.
  $('a').filter(function() {
    return this.hostname && this.hostname != location.hostname;
  }).addClass('external');

[MySQL] How to install mytop on CentOS 5.3

For the ones who don’t know what mytop is, it’s a simple perl script that shows mysql’s porcesses list (SHOW PROCESSLIST) like top does for system’s processes. First of all, let’s assure what distro you’re using by typing:

[root@localhost ~]# cat /etc/issue
CentOS release 5.3 (Final)
Kernel \r on an \m

rpm --import http://dries.ulyssis.org/rpm/RPM-GPG-KEY.dries.txt

rpm -Uhv http://bit.ly/DVVs1
yum install rpm

vim ~/.bashrc
alias mytop='mytop -uuser -ppass'