Hi,
We have a VPS account. It still has PHP 4 installed and we want to upgrade to PHP 5. We asked support for possible pitfalls. Among others, this is what was in their reply:
I understand you are using PHP with MySQL, as for your other issue, but often databases created in a PHP 4 environment do not import correctly into a PHP 5 environment.
Does this make sense?
Thanks!
It makes perfect sense... in the sense that whomever you talked to has no idea what they're talking about. 
That's like your local car dealership saying your car might not function properly if you switch from taking showers to taking baths. MySQL is completely independent from PHP. Which version of PHP you're using has no bearing on how MySQL functions, let alone whether or not a database will work or not.
Thanks!
That's exactly what I thought... PHP is used as a bridge to MySQL, a pure mySQL query is passed to MySQL through PHP but it is the contents of the query that finally does the job in MySQL, right?
That person has repeatedly mentioned that databases on the server created through PHP 4 can cause issues when upgrading to PHP 5...
The only issue I can think of that is PHP-related is that the original mysql_*() functions are not installed by default in PHP 5: you have to specifically enable them as part of the installation. (Whereas the "improved" MySQLi functions are installed). So you do need to make sure your PHP 5 installation has the old MySQL extension installed if you still need to be backwards compatible with it.
