ShopSite does provide a way to upload and download your product/page database information in standard XML format. While there is little or no documentation on ShopSite's internal database format, XML is an industry standard data format well documented. ShopSite does support database manipulation through XML, though perhaps not as powerful as an SQL interface.
If you have a knowledge of Perl, PHP, C, or some programming language, and the right server setup, you could create a program to interact with your database in XML format. ShopSite provides documentation and sample scripts to help you get started. Here are a few helpful resources:
Getting data in and out of your product/pages database:
http://www.shopsite.com/help/8.3/en-US/sc/pro/database.automated_XML_upload.html
Detailed List of Upload/Download Parameters:
http://www.shopsite.com/help/8.3/en-US/sc/pro/index.htm?page=/help/8.3/en-US/sc/pro/upload.fields.html