http://www.swissql.com/products/sqlone-apidotnet/sqlone-apidotnet.html
Generally this is handled on the side of the developer. There have been some developers run all of their queries through a third-party product that allows the "from" and "to" database languages to be specified and it converts on the fly. Others know that they will either be dealing with one or two langauges and program the logic accordingly in the BO.
Hope this helps.