How to retrieve and display data in JSON format from a database using PDO in PHP?

To retrieve and display data in JSON format from a database using PDO in PHP, you can follow these steps:

Establish the database connection using PDO:

<?php
$dns = 'mysql:host=localhost;dbname=your_database_name';
$username = 'your_username';
$password = 'your_password';

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

Prepare and execute the SQL query to fetch data:

<?php
$sql = "SELECT * FROM your_table_name";
$stmt = $pdo->prepare($sql);
$stmt->execute();
?>

Fetch the data from the executed query and store it in an associative array:

<?php
$result = array();
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    $result[] = $row;
}
?>

Convert the fetched data array into JSON format:

<?php
$jsonData = json_encode($result);
?>

Set appropriate headers to indicate that the response is in JSON format:

<?php
header('Content-Type: application/json');
?>

Finally, echo or display the JSON data:

<?php
echo $jsonData;
?>

This code will retrieve all the data from the specified table and display it in JSON format when executed. Adapt the code by replacing "your_database_name", "your_username", "your_password", and "your_table_name" with your actual values.