How to fetch data from a database using different fetch styles in PDO in PHP?

PDO (PHP Data Objects) is a PHP extension that provides a consistent interface for accessing databases. It supports various fetch styles to retrieve data from a database. Here's how you can use different fetch styles in PDO:

Default fetch style (PDO::FETCH_BOTH):
- This is the default fetch style.
- It returns an array indexed by both column name and 0-indexed column number.
- Example usage:

$pdo = new PDO("mysql:host=localhost;dbname=mydatabase", "username", "password");
$stmt = $pdo->prepare("SELECT * FROM users");
$stmt->execute();

// Fetch data using default fetch style
while ($row = $stmt->fetch()) {
    echo $row['column_name'] . ' - ' . $row[0] . "\n";
}

Fetch style - PDO::FETCH_ASSOC:
- It returns an associative array indexed by column name.
- Example usage:

$stmt = $pdo->prepare("SELECT * FROM users");
$stmt->execute();

// Fetch data using associative fetch style
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    echo $row['column_name'] . "\n";
}

Fetch style - PDO::FETCH_NUM:
- It returns an array indexed by 0-indexed column number.
- Example usage:

$stmt = $pdo->prepare("SELECT * FROM users");
$stmt->execute();

// Fetch data using numeric fetch style
while ($row = $stmt->fetch(PDO::FETCH_NUM)) {
    echo $row[0] . "\n";
}

Fetch style - PDO::FETCH_OBJ:
- It returns an anonymous object with property names that correspond to the column names.
- Example usage:

$stmt = $pdo->prepare("SELECT * FROM users");
$stmt->execute();

// Fetch data using object fetch style
while ($row = $stmt->fetch(PDO::FETCH_OBJ)) {
    echo $row->column_name . "\n";
}

These are some of the commonly used fetch styles in PDO to retrieve data from a database. You can choose the fetch style that best suits your needs.