[Zope] Close Database Connection /Newbie Question

Hello! Could someone please help me? In a little python-product I open a connection to Mysql like that: db = self.ZMySQL_Connection() With db.query("SQL") i send requests to the database. It works fine. But after a while I get an error "too many connections". Seems logical for me, because I don't close the connection. But how do I close it? Something like db.close() doesn't work. Thanks in advance Philipp