HP 3000 Manuals HP 3000 Manuals
Chapter 4 Host Variables Host variables are data items used in SQL commands in both the main program unit and in subprogram units. They are used to pass the following information between an application program and ALLBASE/SQL: * Data values. * Null value indicators. * Dynamic commands. * Savepoint numbers. * Messages from the ALLBASE/SQL message catalog. * DBEnvironment Names All host variables used in either the main program unit or a subprogram unit of a FORTRAN program must be declared in the Host Variable Declaration Section of the program unit where the host variable is used. The type descriptions of host variables must be compatible with ALLBASE/SQL data types. The type descriptions of host variables must also satisfy certain preprocessor criteria. This chapter first identifies how and where in a program unit you can use host variables. Then it discusses how to write variable declaration types that complement the way they are used.