Very ofter web service works as an interface (limited or full) to DB, and basically the goal of web service is to update the db from request and/or send the response from DB as well. The purpose of WS in this situation is to map incoming XML to SQL statment(e.g using XSLT). One of the solution I know is Sonic Integration workbench but it's too expensive and very heavy.
I would see it as a simple Axis or Xfire application having XSD for SQL resultset and some mapping between incoming and outgoing XML and DB resultset's XML
I wounder if somebody uses any solution like this?