[Input] Data source name. The data might be located on the same computer as the program, or on another computer somewhere on a network. For information about how an application chooses a data source, see Choosing a Data Source or Driver.
[Input] Length of *ServerName in characters.
[Input] User identifier.
[Input] Length of *UserName in characters.
[Input] Authentication string (typically the password).
Whenever a driver returns SQL_ERROR or SQL_INVALID_HANDLE, the Driver Manager returns the error to the application (in SQLConnect or SQLDriverConnect).
Whenever a driver returns SQL_SUCCESS_WITH_INFO, the Driver Manager will obtain the diagnostic information from hDbcInfoToken, and return SQL_SUCCESS_WITH_INFO to the application in SQLConnect and SQLDriverConnect.
Applications should not call this function directly. An ODBC driver that supports driver-aware connection pooling must implement this function.