[TYPO3-UG France] A connection an external database with SQL

[pcsystemd at free.fr]

Hello,
I would like to communicate with another database external Typo3 to retrieve
information and display a page.

Example:

I have a database other than Typo3 containing personal information of visitors.
I wish to appeal this basis and see them on a page.

My question:

it is possible to override a global variable or create an extension that would
appeal to this base (with the login) and sql queries? Or you know another
solution?

Thank you very much