How important is it to specify the database connection parameter in mysqli functions compared to mysql functions in PHP?

When using mysqli functions in PHP, it is crucial to specify the database connection parameter in each function call, as mysqli requires a connection object to operate on. This ensures that the function knows which database connection to use for executing queries. This is different from mysql functions, where the connection parameter is not required in each function call. Failing to specify the database connection parameter in mysqli functions will result in errors or unexpected behavior.

// Create a database connection
$connection = mysqli_connect('localhost', 'username', 'password', 'database');

// Example of using mysqli_query with the database connection parameter
$query = "SELECT * FROM table";
$result = mysqli_query($connection, $query);

// Example of using mysqli_fetch_assoc with the database connection parameter
while ($row = mysqli_fetch_assoc($result)) {
    // Process the data
}

// Remember to close the database connection when done
mysqli_close($connection);