How can PHP developers ensure proper error handling when a code is not found in the database during a query?

When a code is not found in the database during a query, PHP developers can ensure proper error handling by checking if the query returned any results and then handling the case where no results are found gracefully. This can be done by using conditional statements to check if any rows were returned from the query and displaying an appropriate message or taking alternative actions if no results are found.

// Perform the database query
$result = mysqli_query($connection, "SELECT * FROM table WHERE code = 'your_code'");

// Check if any rows were returned
if(mysqli_num_rows($result) > 0) {
    // Code found, fetch the data
    $row = mysqli_fetch_assoc($result);
    // Process the data
} else {
    // Code not found, display an error message or take alternative actions
    echo "Code not found in the database.";
}

// Free the result set
mysqli_free_result($result);