KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q148745: PRB: DAO Can’t Be Used in an ISAPI DLL

Article: Q148745
Product(s): Microsoft C Compiler
Version(s): 4.0,4.1
Operating System(s): 
Keyword(s): kbDAOsearch kbDatabase kbMFC kbVCkbbuglist
Last Modified: 13-FEB-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- The DAO SDK, included with:
   - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1 
-------------------------------------------------------------------------------


SYMPTOMS
========

DAO fails inside an ISAPI DLL. A call to CoGetClassObject() or
CoCreateInstance() for the database engine will fail. You may receive the
following HRESULTS:

E_OUTOFMEMORY                  (    0x8007000EL )
REGDB_E_IIDNOTREG            (    0x80040155L )

CAUSE
=====

DAO wasn't tested or designed to work in an ISAPI DLL. The problem lies within
the way the Internet Information Server handles OLE.

RESOLUTION
==========

Do one of the following:

- Don't use DAO. Because DAO is non-thread safe, Microsoft recommends that you
  not use it in an ISAPI DLL. The SQL Server ODBC driver works well with an
  ISAPI DLL and is a good choice for scaleable solutions.

  -or-

- Use the Internet Data Connector feature of the Microsoft Internet Information
  Server to connect to the database file. See the online documentation for the
  Microsoft Internet Information Server for more information about the Internet
  Data Connector.

  -or-


- Write a CGI application to get to DAO rather than calling DAO in an ISAPI
  DLL.

STATUS
======

This behavior is by design.

REFERENCES
==========

Tech note 67 (TN067), "Database Access from an ISAPI Server Extension"

Additional query words: 4.00 4.10

======================================================================
Keywords          : kbDAOsearch kbDatabase kbMFC kbVC kbbuglist
Technology        : kbAudDeveloper kbDAOsearch kbSDKDAOSearch kbSDKSearch
Version           : :4.0,4.1
Issue type        : kbprb

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.