MDAC 2.5 SDK - ODBC Programmer's Reference
Appendix G: Driver Guidelines for Backward Compatibility


 

SQLAllocConnect Mapping

When an application calls SQLAllocConnect through an ODBC 3.x driver, the call to SQLAllocConnect(henv, phdbc) is mapped to SQLAllocHandle as follows:

  1. The Driver Manager allocates a connection and returns it to the application.

  2. When the application establishes a connection, the Driver Manager calls
    SQLAllocHandle(SQL_HANDLE_DBC, InputHandle, OutputHandlePtr)
    

    in the driver with InputHandle set to henv, and OutputHandlePtr set to phdbc.