INF: How to Use SQLDataSources() (101519)

SUMMARY

SQLDataSources() enumerates ODBC data source names and is implemented by the ODBC Driver Manager. The 'description' it returns through szDescription is the driver description (as opposed to data source description). This article discusses how this 'description' can be used, and also why the 'description' is not a description of the data source, as the name of this function implies.

MORE INFORMATION

The driver description given to a driver by a driver developer is recorded in the ODBC drivers section in the ODBCINST.INI file. For example, the description for the dBase driver is "dBase Files (*.dbf)." When a data source called Isamdata is set up for this driver, the following entry is made to the ODBC.INI file under the ODBC data sources section:

   [ODBC Data Sources]
   Isamdata = dbase Files (*.dbf)

SQLDataSources() returns "dbase Files (*.dbf)" in szDescription for the Isamdata Data Source. An application can use this by allowing the user to choose File->Open (using the GetOpenFileName() function in the Windows Common Dialog Library) for ISAM files.

The application can call SQLDataSources() to get the driver descriptions for the ODBC data sources, and put the string "(dbase Files)" in the File Name edit control of the Dialog Box. It can then parse the "*.dbf" part from szDescription so that the 'List Files of Type' list box can then be used to limit the files displayed (OPENFILENAME.lpstrFilter for Windows programmers), in this case only *.dbf files. The application can then make a SQLDriverConnect() call to connect to the data source, and make the appropriate ODBC calls to get data from the ISAM file chosen by the user.

It is therefore recommended that driver developers use such descriptions for their drivers for ISAM-type files.