FIX: Visual C++ 5.0 #import Causes Errors with ADO Version 2.0 (190726)


The information in this article applies to:

  • Microsoft Visual C++, 32-bit Enterprise Edition 5.0
  • Microsoft Visual C++, 32-bit Professional Edition 5.0
  • ActiveX Data Objects (ADO) 2.0
This article was previously published under Q190726

SYMPTOMS

On a clean Windows 95 or Windows 98 machine with DCOM95 or DCOM98 installed, compile the following in a .cpp file: 
#import "c:\program files\common files\system\ado\msado15.dll"
RESULT: You get the following error messages: 
   error C2504: '_Connection15' : base class undefined
					
   error C2504: '_Recordset15' : base class undefined
					
   error C2504: 'Fields15' : base class undefined
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Connection *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::_Recordset *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::Fields *const ' to 'struct IUnknown *'
					
   error C2664: '_com_issue_errorex' : cannot convert parameter 2 from
                'struct ADODB::Fields *const ' to 'struct IUnknown *'
NOTE: This problem also occurs on Windows NT 4.0, and the resolution given applies.

CAUSE

This is a problem in the #import feature of the compiler.

RESOLUTION

To work around this problem, use one of the following alternatives:

  • Install Visual Studio 97, Service Pack 3.
  • Upgrade to Visual C++, version 6.0.
  • Modify the resultant .tlh file by moving each of the declarations for

    _Connection15, _Recordset15, and Field15

    ahead of each of the declarations for

    Connection, Recordset, and Field.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. The problem has been corrected in Visual Studio 97, Service Pack 3, and also in Visual C++ version 6.0.

REFERENCES

For additional information about how to obtain Visual Studio 97, Service Pack 3, please see the following article in the Microsoft Knowledge Base:

170365 Visual Studio 97 Service Packs - What, Where, and Why

Modification Type:MajorLast Reviewed:11/18/2003
Keywords:kbBug kberrmsg kbfix kbVC600fix KB190726
©2003 Microsoft Corporation. All rights reserved.