What are some best practices for selecting a random subset of entries from a database using PHP?

When selecting a random subset of entries from a database using PHP, one common approach is to retrieve all entries from the database and then randomly select a subset of them. This can be achieved by fetching all entries into an array, shuffling the array, and then selecting a specified number of entries from the shuffled array. 

// Connect to the database
$pdo = new PDO('mysql:host=localhost;dbname=database_name', 'username', 'password');

// Fetch all entries from the database
$stmt = $pdo->query('SELECT * FROM table_name');
$entries = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Shuffle the array
shuffle($entries);

// Specify the number of entries to select
$numEntries = 5;

// Select a random subset of entries
$randomSubset = array_slice($entries, 0, $numEntries);

// Output the random subset
print_r($randomSubset);

Keywords

random subset database PHP query sampling

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