What are common pitfalls when updating large amounts of data in a MySQL database using PHP?

One common pitfall when updating large amounts of data in a MySQL database using PHP is not using transactions. Transactions ensure that all changes are atomic and either all succeed or all fail, preventing data inconsistencies. To solve this, wrap your update statements in a transaction block. 

// Establish a connection to the database
$pdo = new PDO("mysql:host=localhost;dbname=mydatabase", "username", "password");

// Begin a transaction
$pdo->beginTransaction();

try {
    // Update large amounts of data
    $stmt = $pdo->prepare("UPDATE mytable SET column = :value WHERE condition = :condition");
    
    foreach ($dataToUpdate as $row) {
        $stmt->execute([
            'value' => $row['value'],
            'condition' => $row['condition']
        ]);
    }

    // Commit the transaction if all updates were successful
    $pdo->commit();
} catch (PDOException $e) {
    // Rollback the transaction if an error occurred
    $pdo->rollBack();
    echo "Error updating data: " . $e->getMessage();
}

Keywords

MySQL PHP database update performance transaction handling

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