Establish object-oriented PHP database connection using PDO

Use PHP Data Objects (PDO) to establish object-oriented PHP database connections, providing a unified interface for interacting with various databases. The establishment of a PDO connection requires a data source name (DSN), username and password. Use the query() method to execute SQL queries and the fetchAll() method to obtain results. Practical examples show how to connect a PHP form to a MySQL database and insert data.

Use PDO to establish an object-oriented PHP database connection

Object-oriented PHP database connection uses the PHP Data Object (PDO) class Library that provides a unified interface for interacting with various databases. Using PDO, you access the database in an object-oriented manner, which makes the code easier to organize and maintain.

Establishing a PDO connection

To establish a PDO connection, you need to use the PDO constructor. This constructor accepts the following parameters:

• Data source name (DSN): Specifies the database server, database name, and other database-specific connection information. The format of the DSN varies depending on the database type.
• Username: Username to connect to the database.
• Password: Password to connect to the database.

$dsn = 'mysql:host=localhost;dbname=my_database';
$username = 'root';
$password = '';

try {
  $pdo = new PDO($dsn, $username, $password);
} catch (PDOException $e) {
  echo 'Connection failed: ' . $e->getMessage();
  die();
}

Execute query

You can use the query() method to execute a SQL query. This method returns a PDOStatement object that represents the query results.

$sql = 'SELECT * FROM users WHERE name LIKE ?';
$stmt = $pdo->prepare($sql);
$stmt->execute(['%joh%']);

Get the results

You can get the query results through the fetchAll() method. This method returns a result array where each element is an associative array.

$users = $stmt->fetchAll(PDO::FETCH_ASSOC);

Practical Example

Consider a basic PHP form where a user can enter their name and insert it into a database. We use PDO to connect this form to a MySQL database.

<!-- form.php -->
<form action="submit.php" method="post">
  <label for="name">姓名:</label>
  <input type="text" id="name" name="name">
  <input type="submit" value="提交">
</form>

// submit.php
$dsn = 'mysql:host=localhost;dbname=my_database';
$username = 'root';
$password = '';

try {
  $pdo = new PDO($dsn, $username, $password);
} catch (PDOException $e) {
  echo 'Connection failed: ' . $e->getMessage();
  die();
}

$name = $_POST['name'];
$sql = 'INSERT INTO users (name) VALUES (?)';
$stmt = $pdo->prepare($sql);
$stmt->execute([$name]);

header('Location: success.php');

<!-- success.php -->
<h1 id="成功">成功！</h1>
<p>您的姓名已添加到数据库中。</p>

This example demonstrates how to use PDO to connect a PHP form to a MySQL database and insert data.

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