Month: August 2014

The mysqli extension, or as it is sometimes known, the MySQL improved extension, was developed to take advantage of new features found in MySQL systems versions 4.1.3 and newer

The mysqli extension has a number of benefits, the key enhancements over the mysql extension being:

– Object-oriented interface

– Support for Prepared Statements

– Support for Multiple Statements

– Support for Transactions

– Enhanced debugging capabilities

– Embedded server support

$mysqli = new mysqli("example.com", "user", "password", "database");
if ($mysqli->connect_errno) {
echo "Failed to connect to MySQL: " . $mysqli->connect_error;
}

echo 'Total results: ' . $res->num_rows;


$statment = $db->prepare("SELECT `name` FROM `users` WHERE `username` = ? and `age` = ?");
$statement->bind_param('si', $name, $age);
$statement->execute();
$result = $statement->get_result();
while($row = $result->fetch_array(MYSQLI_ASSOC)){
}


In bind param, first parameter denotes the types “s for string, i for integer, d for decimal, etc)

http://codular.com/php-mysqli

PDO provides a data-access abstraction layer, which means that, regardless of which database you’re using, you use the same functions to issue queries and fetch data.

try {
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
foreach($dbh->query('SELECT * from FOO') as $row) {
print_r($row);
}
$dbh = null;
} catch (PDOException $e) {
print "Error!: " . $e->getMessage() . "
";
die();
}

// Persistent Connections
true
));
?>

Prepared Statements :
They can be thought of as a kind of compiled template for the SQL that an application wants to run, that can be customized using variable parameters. Prepared statements offer two major benefits:
a) The query only needs to be parsed (or prepared) once, but can be executed multiple times with the same or different parameters.
b) The parameters to prepared statements don’t need to be quoted; the driver automatically handles this. If an application exclusively uses prepared statements, the developer can be sure that no SQL injection will occur

$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (:name, :value)");
$stmt->bindParam(':name', $name);
$stmt->bindParam(':value', $value);

// insert one row
$name = 'one';
$value = 1;
$stmt->execute();

// repeated inserts
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (?, ?)");
$stmt->bindParam(1, $name);
$stmt->bindParam(2, $value);

// fetching data
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name = ?");
if ($stmt->execute(array($_GET['name']))) {
while ($row = $stmt->fetch()) {
print_r($row);
}
}

PDO vs mysqli :
While PDO has its advantages, such as a clean, simple, portable API, its main disadvantage is that it doesn’t allow you to use all of the advanced features that are available in the latest versions of MySQL server. For example, PDO does not allow you to use MySQL’s support for Multiple Statements.

PDO works with several databases whereas MySQLi works with MySQL only.

PDO has named parameters whereas MySQLi does not.
$pdo->prepare(‘SELECT * FROM users WHERE username = :username AND email = :email’);
$params = array(‘:username’ => ‘test’, ‘:email’ => $mail);

$mysqli->prepare(‘SELECT * FROM users WHERE username = ? AND email = ?’);
$query->bind_param(‘test’, $mail);

http://code.tutsplus.com/tutorials/pdo-vs-mysqli-which-should-you-use–net-24059

The PHP output buffering will save all the server outputs ( html and php prints) to a string variable.

So to start buffering, use ob_start(); this will keep saved any output.
Then you use $variable = ob_get_clean(); to stop buffering, and copy the buffer content to the variable.

Here are few samples of the use of ob_start() and ob_get_clean()

ob_start(); //Turn on output buffering ?>
Hello world, link
Content
$var = ob_get_clean(); ?> //copy current buffer contents into $message variable and delete current output buffer

http://daylerees.com/php-namespaces-explained

Previously in PHP you can’t have two classes that share the same name. They have to be unique. The issue with this restriction is that if you are using a third party library which has a class named User, then you can’t create your own class also called User. This is a real shame, because that’s a pretty convenient class name right?

PHP namespaces allow us to circumvent this issue, in fact we can have as many User classes as we like. Not only that, but we can use namespaces to contain our similar code into neat little packages, or even to show ownership.

Using a class declared in a namespace

Classes in Global namespace can also be referred as :

$eddard = new \Eddard();

Namespaces can have as many levels of hierarchy as they need to.

This\Namespace\And\Class\Combination\Is\Silly\But\Works