What is the difference between using COUNT() and mysql_num_rows() to count results in PHP?

When counting results in PHP, it is better to use the COUNT() function in your MySQL query rather than the mysql_num_rows() function after executing the query. Using COUNT() directly in the query is more efficient as it performs the counting operation at the database level, resulting in faster performance. On the other hand, mysql_num_rows() retrieves all rows from the result set and then counts them in PHP, which can be slower for large result sets.

// Using COUNT() function in MySQL query to count results
$query = "SELECT COUNT(*) AS total_rows FROM your_table";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_assoc($result);
$total_rows = $row['total_rows'];
echo "Total rows: " . $total_rows;