Should I have to upgrade my website to PHP MySQLi or PDO?

Question

I have designed a website before 5 years using PHP MySQL and still works fine without any issues. I heard MySQL is officially deprecated as of PHP 5.5 and has been removed a

Answer 1

The answer is fairly simple.

If, like majority of PHP users, you are going to use database API functions right in the application code, without any intermediate wrapper, then PDO is your only choice, as it's a sort of wrapper already, automating many operations that with mysqli have to be done manually.

No, there are no migration options, because the very approach is changed dramatically: instead of placing variables right in the query, they have to be substituted in the query with special marks. There is no way to automate this process.