Defining ODBC

The ODBC Driver Manager

An application communicates with the ODBC Driver Manager through the ODBC interface. The Driver Manager exists as a DLL that loads ODBC drivers.

Figure 6.12 The ODBC Driver Manager

In addition to loading the necessary drivers, the Driver Manager:

  • Processes several ODBC initialization and information calls.
  • Passes ODBC function calls from application to driver.
  • Performs error and state checking.
  • Logs function calls made by applications (optional).

An application typically links with the Driver Manager import library file odbc.lib to gain access to the Driver Manager.

When an application calls an ODBC function, the Driver Manager can optionally record each executed function in a trace file. This occurs after checking the function call for errors. The name of each error-free function is recorded, along with the values of the input arguments and the names of the output arguments.

The Driver Manager also checks function arguments and state transitions, and for other error conditions before passing the call to the driver associated with the connection. This reduces the amount of error handling that a driver needs to perform.



Microsoft Windows Architecture Training
Microsoft Windows Architecture for Developers Training Kit
ISBN: B00007FY9D
EAN: N/A
Year: 1998
Pages: 324

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