ODBCLINK/SE Reference Manual (36217-90410)

ODBCLink/SE Reference Manual Overview and Specifications
ODBCLink/SE
©M.B. Foster Associates Limited 1995-2000 3
Microsoft ODBC Overview
ODBC applications make functions calls into ODBC32.DLL, the Microsoft driver manager. Since a single
application can make calls to more than one ODBC database (e.g. Sybase, Microsoft SQL server) the driver manager
is in charge of routing ODBC calls to the appropriate driver. The ODBC.INI file contains a list of drivers and
associated data sources (one driver may have several data-sources). In Windows 95 or NT, some of this information
is kept in the system registry.
To connect to an ODBC database, you call SQLDriverConnect (or you let your ODBC-compliant application call it
for you) and specify your data-source name in the connection string variable, which is in the form
"DSN=data_source”. The driver manager reads ODBC.INI or the registry, to find out which driver handles that data
source and passes the call on to the driver. The driver opens the communication channel and does all necessary
initialization.
The ODBC.INI file (or the ODBC System Registry) is maintained through the ODBC Control Panel application
ODBCADM.EXE , or the 32-bit ODBC Control Panel application ODBCAD32.EXE. The control panel application
will call the setup DLL for the driver it is accessing ODBCLS32.DLL, in the case of ODBCLink/SE, which will
update ODBC.INI or the system registry.