How can PHP developers improve the efficiency and readability of their code when working with MySQL queries?

PHP developers can improve the efficiency and readability of their code when working with MySQL queries by using prepared statements. Prepared statements separate the SQL query from the data, preventing SQL injection attacks and improving performance by allowing the database to optimize query execution. Additionally, using parameterized queries makes the code more readable and maintainable.

// Example of using prepared statements with MySQL in PHP
$mysqli = new mysqli("localhost", "username", "password", "database");

// Prepare a SQL statement
$stmt = $mysqli->prepare("SELECT * FROM users WHERE username = ?");

// Bind parameters
$stmt->bind_param("s", $username);

// Set parameters and execute
$username = "john_doe";
$stmt->execute();

// Get results
$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
    // Process results
}

// Close statement and connection
$stmt->close();
$mysqli->close();