in reply to
DBD mysql can't detect mysql installation
That's OK. You can connect to your mysql database with DBI->connect(...) even though your databases aren't shown as "known data sources".
The background is that the mysql driver doesn't know which database to connect to (there could be multiple running on your machine, or none at all, and access happens over the network), and which username and password to use.
You can also see that only file-based DBD modules list known data sources, because all the others have the same problems as the mysql driver.