In PHP, what are the best practices for handling salts and ensuring secure password storage in databases?

When storing passwords in databases, it is crucial to use salts to add an extra layer of security. Salts are random strings that are added to passwords before hashing to prevent attackers from using precomputed tables like rainbow tables. To ensure secure password storage, generate a unique salt for each user and combine it with their password before hashing. Store the salt along with the hashed password in the database.

// Generate a random salt
$salt = bin2hex(random_bytes(16));

// Combine the user's password with the salt
$combined = $password . $salt;

// Hash the combined string using a secure hashing algorithm like bcrypt
$hashedPassword = password_hash($combined, PASSWORD_DEFAULT);

// Store the hashed password and salt in the database
// INSERT INTO users (username, password, salt) VALUES ('$username', '$hashedPassword', '$salt');