How to update a table every 6 hours from xml file

Hello. I have this problem. I have i site with classifieds based on mysql and i want to put products from e-shops. One e-shop wants me to update my data base every 6 hours from an xml file or csv file they will put to a url. The questions are : Every 6 hours i have to delete the old products from the e-shop and put the new ones or there is a better way? How i will call the script for the update every 6 hours?Is there any script for putting xml data to mysql? Thanks very much

re: How to update a table every 6 hours from xml file

To run a script every 6 hours you set cronjob. Most of the control panels have the interface to set cronjobs easily e.g. CPanel.

To import XML you can DOM XML.