Description

   The SCA$GET_OCCURRENCE routine returns an occurrence from the
   query specified by the query_name argument.

   If the occurrence handle supplied is zero, the routine returns
   a handle to the first occurrence in the query represented by the
   argument query_name. If the occurrence handle supplied on input
   represents a valid occurrence, the routine returns a handle to
   the next occurrence in the query result. In order to be valid, the
   occurrence handle supplied on input must refer to an occurrence in
   the query represented by the argument query_name.

   The query name supplied is interpreted in the context of the
   command context identified by the argument command_context.

   Note that the order of retrieval of the occurrences is undefined.