PHP programming tips: utilizing Mysql functions

Although PHP provides us with many functions, some things are still not very convenient to deal with. For example, the date and time functions provided by PHP are very limited. MySQL provides us with many such functions. Can I use Mysql functions to process PHP programs? The author made the following attempts.
$data_time="1998-12-31 23:59:59";
$connect_id=mysql_connect('localhost');
$query_id=mysql_query("SELECT DATE_ADD('$data_time',INTERVAL 1 YEAR)",$connect_id);
$data_time=mysql_result($query_id,0);
Mysql_close($connect_id);
echo $data_time;
?>

By analogy, we can also use other functions provided by Mysql during the programming process.
Of course, please check the manual for the functions and usage provided by Mysql.
Please correct me if I am inappropriate!

The above introduces PHP programming skills: using Mysql functions, including PHP skills and Mysql functions. I hope it will be helpful to friends who are interested in PHP tutorials.