THE WORLD'S LARGEST WEB DEVELOPER SITE

PHP Tutorial

PHP HOME PHP Intro PHP Install PHP Syntax PHP Comments PHP Variables PHP Echo / Print PHP Data Types PHP Strings PHP Numbers PHP Constants PHP Operators PHP If...Else...Elseif PHP Switch PHP While Loops PHP For Loops PHP Functions PHP Arrays PHP Sorting Arrays PHP Superglobals

PHP Forms

PHP Form Handling PHP Form Validation PHP Form Required PHP Form URL/E-mail PHP Form Complete

PHP Advanced

PHP Arrays Multi PHP Date and Time PHP Include PHP File Handling PHP File Open/Read PHP File Create/Write PHP File Upload PHP Cookies PHP Sessions PHP Filters PHP Filters Advanced

PHP OOP

PHP What is OOP PHP Classes/Objects PHP Constructor PHP Destructor PHP Access Modifiers PHP Inheritance PHP Constants PHP Abstract Classes PHP Traits PHP Static Methods

MySQL Database

MySQL Database MySQL Connect MySQL Create DB MySQL Create Table MySQL Insert Data MySQL Get Last ID MySQL Insert Multiple MySQL Prepared MySQL Select Data MySQL Delete Data MySQL Update Data MySQL Limit Data

PHP XML

PHP XML Parsers PHP SimpleXML Parser PHP SimpleXML - Get PHP XML Expat PHP XML DOM

PHP - AJAX

AJAX Intro AJAX PHP AJAX Database AJAX XML AJAX Live Search AJAX Poll

PHP Examples

PHP Examples PHP Quiz PHP Exercises PHP Certificate

PHP Reference

PHP Overview PHP Array PHP Calendar PHP Date PHP Directory PHP Error PHP Filesystem PHP Filter PHP FTP PHP Libxml PHP Mail PHP Math PHP Misc PHP MySQLi PHP Network PHP SimpleXML PHP Stream PHP String PHP XML Parser PHP Zip PHP Timezones

PHP Connect to MySQL


PHP 5 and later can work with a MySQL database using:

  • MySQLi extension (the "i" stands for improved)
  • PDO (PHP Data Objects)

Earlier versions of PHP used the MySQL extension. However, this extension was deprecated in 2012.


Should I Use MySQLi or PDO?

If you need a short answer, it would be "Whatever you like".

Both MySQLi and PDO have their advantages:

PDO will work on 12 different database systems, whereas MySQLi will only work with MySQL databases.

So, if you have to switch your project to use another database, PDO makes the process easy. You only have to change the connection string and a few queries. With MySQLi, you will need to rewrite the entire code - queries included.

Both are object-oriented, but MySQLi also offers a procedural API.

Both support Prepared Statements. Prepared Statements protect from SQL injection, and are very important for web application security.


MySQL Examples in Both MySQLi and PDO Syntax

In this, and in the following chapters we demonstrate three ways of working with PHP and MySQL:

  • MySQLi (object-oriented)
  • MySQLi (procedural)
  • PDO

MySQLi Installation

For Linux and Windows: The MySQLi extension is automatically installed in most cases, when php5 mysql package is installed.

For installation details, go to: http://php.net/manual/en/mysqli.installation.php


PDO Installation

For installation details, go to: http://php.net/manual/en/pdo.installation.php



Open a Connection to MySQL

Before we can access data in the MySQL database, we need to be able to connect to the server:

Example (MySQLi Object-Oriented)

<?php
$servername = "localhost";
$username = "username";
$password = "password";

// Create connection
$conn = new mysqli($servername, $username, $password);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>

Note on the object-oriented example above:

$connect_error was broken until PHP 5.2.9 and 5.3.0. If you need to ensure compatibility with PHP versions prior to 5.2.9 and 5.3.0, use the following code instead:

// Check connection
if (mysqli_connect_error()) {
    die("Database connection failed: " . mysqli_connect_error());
}

Example (MySQLi Procedural)

<?php
$servername = "localhost";
$username = "username";
$password = "password";

// Create connection
$conn = mysqli_connect($servername, $username, $password);

// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
echo "Connected successfully";
?>

Example (PDO)

<?php
$servername = "localhost";
$username = "username";
$password = "password";

try {
    $conn = new PDO("mysql:host=$servername;dbname=myDB", $username, $password);
    // set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected successfully";
    }
catch(PDOException $e)
    {
    echo "Connection failed: " . $e->getMessage();
    }
?>

Note: In the PDO example above we have also specified a database (myDB). PDO require a valid database to connect to. If no database is specified, an exception is thrown.

Tip: A great benefit of PDO is that it has an exception class to handle any problems that may occur in our database queries. If an exception is thrown within the try{ } block, the script stops executing and flows directly to the first catch(){ } block.


Close the Connection

The connection will be closed automatically when the script ends. To close the connection before, use the following:

MySQLi Object-Oriented:

$conn->close();

MySQLi Procedural:

mysqli_close($conn);

PDO:

$conn = null;