PHP PDO

PHP PDO (PHP Data Objects) is a lightweight, consistent interface for accessing databases in PHP. PDO provides a data-access abstraction layer, which means that, regardless of which database we are working on, we must use the same PDO functions to work with databases.

Syntax

$pdo = new PDO('mysql:host=hostname;dbname=database_name', $username, $password);

Example

// Establishing the connection
$pdo = new PDO('mysql:host=localhost;dbname=test', $username, $password);

// Creating a query
$sql = "SELECT * FROM users";

// Executing the query
$result = $pdo->query($sql);

// Fetching the result set
foreach($result as $row) {
    echo $row['name'] . "\n";
}

// Closing the connection
$pdo = null;

Output

John
Samuel
Peter

Explanation

• To work with PDO, we first need to establish a connection to the database by creating an instance of the PDO class.
• We pass the database connection details as arguments to the PDO constructor, which include the hostname, database name, username, and password.
• After establishing the connection, we can create a SQL query and execute it using the query() method of the PDO class. This method returns a result set that we can fetch using a loop.
• Finally, we close the connection by setting the $pdo variable to null.

Use

PDO is used to work with different types of databases such as MySQL, PostgreSQL, Oracle, and more. It provides a simple and consistent way of working with these databases, which makes it easier to write database-related code in PHP.

Important Points

• PDO provides a consistent interface for working with different databases in PHP.
• PDO is a lightweight library that does not require any additional installation or configuration.
• PDO supports prepared statements, which help to prevent SQL injection attacks.
• PDO supports transactions, which help to ensure data consistency in the database.

Summary

PHP PDO provides a consistent interface for working with different types of databases in PHP. It is a lightweight library that simplifies database-related code and provides features such as prepared statements and transactions to help ensure data consistency and prevent security vulnerabilities.