This chapter doesn't discuss the ODBC installation; this has to be done by an external setup program in the case of system without ODBC support - all versions of Windows 95.
To learn to how to add/remove license during installation process, see the Using Licenses chapter.
Sequel implementation resides in the sequel.dll file, which must be deployed with your application. As Sequel is the COM server, it must be registered via regsvr32.exe or any similar tool. The recommended location where to place sequel.dll is %Common Files%\XDTK Shared\Sequel directory.
Also the SequelShared routine returns the recommended location. The SequelInstall.dll library is exporting it.
function SequelShared:PANSIChar; stdcall;
char* stdcall SequelShared();
If sequel.dll file is already registered elsewhere than %Common Files%\XDTK Shared\Sequel, this routine will return the current location.
This library also exports routine named NSISSequelShared. It sets $OUTDIR to SequelShared.
Checking Driver Manager
Because Sequel requires ODBC Driver Manager 3.5 or higher (less than this doesn't support UNICODE) and not all versions of Windows have it already installed, the SequelInstall.dll library exports functions to check it and if necessary start the download.
procedure CheckODBC(ADownloadLink:PChar; AWnd:HWND); stdcall;
void stdcall CheckODBC(char *ADownloadLink; HWND AWnd);
If ODBC Driver Manager 3.5 or higher is not found, it displays a dialog with parent window of AWnd (it can be NULL). This dialog asks user for permission to download "Microsoft Jet 4.0 Service Pack 3" from "http://www.microsoft.com/data/download.htm". If user will select Yes, then it will launch the ADownloadLink. Therefore the recommended value of ADownloadLink is http://www.microsoft.com/data/download_Jet4SP3.htm. Specify another string to begin direct download or download from a different site.
GPI-Install version of this routine is named GPICheckODBC and the pAdditional parameter expresses the ADownloadLink, while the NSIS version is named NSISCheckODBC and the ADownloadLink is expected to be in $0.
The code that checks the driver manager is located in the Toolkit, the Delphi section.