Access a printer via PHP

Hello, For an e-commerce project we want to connect the mySQL-database we created to a printer (attached to a computer which has 24h internet [and mySQL database] access). I assume it's different to couple the mySQL-database directly to a printer. We are however accessing the database via PHP, so I think it might be possible to send a command to a printer directly from the PHP file which puts the data into the database as well. We want to do this in order to have an order via the website printed directly. In fact, the printer should start printing as soon as an order is added to the seperate table in the mySQL database (by a special PHP document). Does anyone know whether this is possible and, if it's possible, could you tell me how? Thanks in advance, Thomas.