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Tuesday 13 November 2018

ThinkPHP SQL queries with examples

Question: How to create Model Object?

$userObj= D("Common/Users");

Question: How to add simple AND Query?

$map=array();
$userObj= D("Common/Users");
$map['user_type'] = 2;
$map['city_id'] = 10;
 $lists = $userObj
                ->alias("u")                
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to add simple OR Query?

$map=array();
$userObj= D("Common/Users");
$map['u.username|u.email'] = 'email@domain.com';  //username OR email is email@domain.com
 $lists = $userObj
                ->alias("u")                
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use =, >, < in Query?

$map['id']  = array('eq',1000); //equal to 1000

$map['id']  = array('neq',1000); //Not equal to 1000

$map['id']  = array('gt',1000);//Greater than 1000

$map['id']  = array('egt',1000);//Greater than OR EQual 1000

$map['id']  = array('between','1,8'); //Between 1-8

Question: How to use like Query?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $lists = $userObj
                ->alias("u")                
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use like Query with NOT?

$map=array();
$userObj= D("Common/Users");
$map['b'] =array('notlike',array('%test%','%tp'),'AND'); //Not like %test% and %tp
 $lists = $userObj
                ->alias("u")                
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use Inner JOIN ?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $lists = $userObj
                ->alias("u") 
                ->join(C('DB_PREFIX') . "profile as p ON u.id = p.uid")               
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use LEFT JOIN ?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $lists = $userObj
                ->alias("u") 
                ->join('LEFT JOIN '.C('DB_PREFIX') . "profile as p ON u.id = p.uid")               
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use RIGHT JOIN ?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $lists = $userObj
                ->alias("u") 
                ->join('RIGHT JOIN '.C('DB_PREFIX') . "profile as p ON u.id = p.uid")               
                ->where($map)
                ->order("u.id DESC")
                ->select();

Question: How to use group by and having?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $lists = $userObj
                ->alias("u") 
                ->join('RIGHT JOIN '.C('DB_PREFIX') . "profile as p ON u.id = p.uid")               
                ->where($map)
                ->order("u.id DESC")
                 ->group('u.id')                
                 ->having('count(p.id) >0')
                ->select();

Question: How to use count(for total records)?

$map=array();
$userObj= D("Common/Users");
$map['name'] = array('like','test%'); //like test%
 $count = $userObj
                ->alias("u")                 
                ->where($map)                
                ->count();

Wednesday 20 December 2017

Encapsulation in PHP (OOP)

Question: What is Encapsulation?
The wrapping up of "Data member" and "Member functions" into a single unit (called class) is known as encapsulation.

Question: Describe the Encapsulation?
Encapsulation means hiding the internal details of an object.
OR
Encapsulation is a technique used to protect the information in an object from the other object.

Question: Give Example of the Encapsulation?

class Arithmetic {
    private $first = 10;
    private $second = 50;

    function add() {
        return $this->first + $this->second;
    }

    function multiply() {
        return $this->first * $this->second;
    }

}

//Create the object 
$obj = new Arithmetic( );

//Add Two number
echo $obj->add(); //60
//multiply Two number
echo $obj->multiply(); //500

Friday 10 November 2017

How to replace double quoted string with bold

Question: How to replace double quoted string with bold in PHP?


$description='Hello "dude", how are you?';
echo preg_replace('/"([^"]+)"/', '<strong>$1</strong>', $description);

Output

Hello dude, how are you?

Question: How to replace bracket string with italic in PHP?


$description='Hello (dude), how are you?';
echo preg_replace('/\(([^)]+)\)/', '<i>$1</i>', $description);

Output

Hello dude, how are you?

Tuesday 22 August 2017

How to check if port is active OR Not?

Question: What is fsockopen?
fsockopen — Open Internet or Unix domain socket connection.

Question: How to check if port is open OR Not in particular IP Address OR Domain?

function pingDomainWithPort($domain='localhost',$port=80){
    $starttime = microtime(true);
    $file      = @fsockopen($domain, $port, $errno, $errstr, 10);
    $stoptime  = microtime(true);
    $status    = 0; //in active

    if (!$file) { 
        $status = -1;  // Site is down

    } else {

        fclose($file);
        $status = ($stoptime - $starttime) * 1000;
        $status = floor($status);
    }
    return $status;
}

pingDomainWithPort($_SERVER['REMOTE_ADDR'],1935);
pingDomainWithPort($_SERVER['REMOTE_ADDR'],1458);
pingDomainWithPort($_SERVER['REMOTE_ADDR'],80);
pingDomainWithPort($_SERVER['REMOTE_ADDR'],8080);

You can pass the domain name or Ip Address.

Thursday 17 August 2017

PHP Technical Interview Questions and Answer for 2 year experienced

Question: What is the use of the @ symbol in PHP?
It suppresses error messages, means hide the error/warning messages for that statement.

echo $noDefinedVar;

Question: How to enable all error in PHP?

ini_set('display_startup_errors', 1);
ini_set('display_errors', 1);
error_reporting(-1);

Question: How to disable all error in PHP?

ini_set('display_startup_errors', 0);
ini_set('display_errors', 0);
error_reporting(0);

Question: How to convert a variable to string?

$myVar='123456987';
$myText = (string)$myVar; // Casts to string
var_dump($myText);

Question: How to POST request with PHP?

$ch = curl_init();
$postData='var1=value1&var2=value2&var3=value3';
curl_setopt($ch, CURLOPT_URL, "http://mydomain.com/ajaxurl");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);

echo $result;die;

Question: Formatting a number with leading zeros in PHP?

echo sprintf('%08d', 1234567); //01234567
echo sprintf('%09d', 1234567); //001234567
echo sprintf('%010d', 1234567); //0001234567

Question: How to Check if PHP session has already started?

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

Question: Why do we use ob_start()?

define ("FRUITS", serialize (array ("apple", "mongo", "banana","fig")));
$fruits = unserialize (FRUITS);
print_r($fruits);

Question: How to increase PHP Execution Time?

ini_set('max_execution_time', 300);

Question: how do you change the key of an array element?

$array= array ('a'=>"apple", 'm'=>"mongo", 'b'=>"banana",'f'=>"fig");
print_r($array);
$array['bbbbb']= $array['b'];
unset($array['b']);
print_r($array);

Question: How to get last key in an array?

$array= array ('a'=>"apple", 'm'=>"mongo", 'b'=>"banana",'f'=>"fig");
end($array);
echo key($array);//k

Question: Set HTTP header to UTF-8 using PHP?

header('Content-Type: text/html; charset=utf-8');

Question: How to generate a random, unique, alphanumeric string?

echo md5(uniqid(rand(), true));

Question: How to run SSH Commands from PHP?

$connection = ssh2_connect('HOST_OR_IP_ADDRESS', 'PORT');
ssh2_auth_password($connection, 'USERNAME', 'PASSWORD');

$stream = ssh2_exec($connection, 'ls');
if ($stream) {
        echo "fail: unable to execute command\n";
    } else {
        // collect returning data from command
        stream_set_blocking($stream, true);
        $data = "";
        while ($buf = fread($stream,4096)) {
            $data .= $buf;
            $data.="\n";
        }
        fclose($stream);

        echo $data;
    }

Question: What is output of below?

$a = '1';
$b = &$a;
$b = "2$b";
echo $a.", ".$b;

output
21, 21

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Tuesday 13 November 2018

ThinkPHP SQL queries with examples

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Wednesday 20 December 2017

Encapsulation in PHP (OOP)

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Friday 10 November 2017

How to replace double quoted string with bold

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Tuesday 22 August 2017

How to check if port is active OR Not?

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Thursday 17 August 2017

PHP Technical Interview Questions and Answer for 2 year experienced

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