You can append the path to the INCLUDE environment variable to include the directory where the DB-Library Sqlfront.h and Sqldb.h include files reside. Or you can use the /I compile line switch to point to the include file directory.
Because your Microsoft® Win32®-based applications must always include the Windows.h, Sqlfront.h, and Sqldb.h files, you don’t need to define the DB-Library functions you use. These functions and their proper declarations are already defined in the include file. However, you must define an application’s operating system before including the DB-Library include files. Include the following statements at the beginning of all DB-Library applications designed for the Win32 API:
#define DBNTWIN32
#include <windows.h>
#include <sqlfront.h>
#include <sqldb.h>
You can also define the operating system by using the /D compile line switch (for example, /DDBNTWIN32 instead of a #define declaration).