What is the difference between a functional query definition and SQL?
Functional Query Definitions detail the function(s) to be performed by a query, and the parameter substitution points. They are templates, based on the formal syntax of the ANSI’s Structured Query Language (SQL). A Functional Query Definition (FQD) becomes valid SQL syntax when a permissible value is substituted for each parameter in the FQD, based on the constraints detailed in the Substitution Parameters section of each query definition. The QGEN program is provided to facilitate the generation of executable SQL syntax by supplying acceptable values for the substitution parameters for each query.
