How To Redistributing DAO with Your Visual C++ 5.0 Application

MORE INFORMATION

Redistributing the DAO Setup

On the Visual C++ 5.0 CD, under \DEVSTUDIO\VC\REDIST\DAO\DISK1\, there is a DAO Setup program that can be redistributed. This setup program prompts the user for information about which components to install. You can run the setup program with a '-s' option that silently runs the DAO Setup without putting information on the screen.

Here are a few important notes:

• If you run the program with the -s option, all of the DAO components will be installed (DAO core components, ODBC Direct, and ISAMs).
• If ODBCDirect is selected or you chose the '-s' option, you must have ODBC 3.0 currently installed on the system.
• To register DAO and use DAO, you must have Oleaut32.dll version 2.20.4049 or later as well as Stdole2.tlb installed into your System directory. If you try to run the setup program with the "-s" option and you do not have version 2.20.4049 or later, the setup program fails. To get these newer versions of the files, please see the following article in the Microsoft Knowledge Base:

  180071 FILE: Msvbvm50.exe Installs Visual Basic 5.0 Run-Time Files

Installing the DAO components with Your Own Setup Program

Below is the information from the Daosetup.rtf file installed into the DAO SDK directory.

NOTE: The documentation fails to mention that you must copy the Oleaut32.dll and Stdole2.tlb files from the \devstudio\vc\redist directory on the Visual C++ 5.0 CD into the Windows system directory. You must register Oleaut32.dll.

This document describes the steps required to create a setup program that successfully installs DAO and its related files. It is recommended that you use InstallShield Express that ships with Visual C++ 5.0 along with the information in this document to create your setup.

Proper setup of DAO is very important. Because DAO is a shared component that only exists in one location on a machine, all applications using DAO may stop working if DAO setup is not done correctly.

1. Introduction
   
   To distribute an application that uses DAO, you must install the redistributable portions of DAO. Depending on whether your application uses the Microsoft Jet Engine or ODBCDirect workspaces, you must also install either the redistributable portions of the Microsoft Jet Database Engine, the redistributable portions of the Remote Database Objects (RDO), or both.
   
   DAO, Microsoft Jet, and RDO require a more complex installation procedure than simply copying files into a directory. An application cannot have its own "private" copy of an OLE Automation server (such as DAO) in an application directory. The server is registered by OLE, and all users use the same DLL.
2. Files
   
   DAO and DAO's ODBCDirect each require a core set of files. Microsoft Jet also has a core and a second optional set that provides the ability to access other data formats.
   
   Whether your application uses ODBCDirect or the Microsoft Jet Engine to access data determines whether you should install the Microsoft Jet Engine or ODBCDirect files.
   
   Only the files described in this section can be distributed with your application to other users. You cannot distribute other files, such as .hlp files or DAO header (.h) files.
   
   NOTE: The DAO directory and System32 directory are explained in section 3.2.
   
   
   1. DAO
      
      DAO is comprised of the following core files (these files must be installed for DAO to function):

            File         Description          Installed   Registered  Directory
            -------------------------------------------------------------------
            
            DAO350.DLL    DAO version 3.5      Shared        Yes       DAO
            DAO2535.TLB   Type Library         Companion     No        DAO
                                               to DAO350.DLL
            MSJTER35.DLL  Microsoft Jet        System        No        System32
                          (and DAO) error
                          message DLL
            MSJINT35.DLL  Localized Microsoft  System        No        System32
                          Jet (and DAO) error
                          strings
            MSVCRT40.DLL  C Runtime DLL        System        No        System32
          
      								

   2. Microsoft Jet Engine
      
      
      1. Core Jet files
         Microsoft Jet is comprised of the following core files. These files are sufficient to access version 3.0 .MDB databases and ODBC data sources (in conjunction with an installed ODBC driver) when installed with DAO.

               File         Description          Installed   Registered  Directory
               -------------------------------------------------------------------
               
               MSJET35.DLL  Microsoft Jet engine  System         Yes     System32
                            (version 3.5)
               MSRD2X35.DLL MDB files from       Companion       Yes     System32
                            Microsoft Access     to MSJET35.DLL
                            2.0, Visual Basic
                            3.0 or earlier
               MSJTER35.DLL Microsoft Jet (and   System          No      System32
                            DAO) error message
                            DLL
               MSJINT35.DLL Localized Microsoft  System          No      System32
                            Jet (and DAO) error
                            strings
               VBAJET32.DLL VBA-Microsoft Jet    System          No      System32
                            Expression service
               VBAR332.DLL  VBA Runtime          System          No      System32
             
         										

      2. Optional files
         The following optional files provide access to other data formats. Install the DLLs that correspond to the file format you need to support, or if you need replication support.

               Module        Description         Installed   Registered  Directory
               -------------------------------------------------------------------
               
               MSREPL35.DLL  Microsoft Jet       System      No          System32
                             Replication
               MSXBSE35.DLL  Xbase formats       System      Yes         System32
               MSPDOX35.DLL  Paradox formats     System      Yes         System32
               MSTEXT35.DLL  Text files          System      Yes         System32
               MSEXCL35.DLL  Spreadsheet files   System      Yes         System32
               MSLTUS35.DLL  Lotus formats       System      Yes         System32
               MSEXCH35.DLL  Exchange formats    System      Yes         System32
                
         										

   3. ODBCDirect
      
      Install the following files for supporting ODBCDirect functionality. DAO uses RDO to handle it's ODBCDirect functionality. For this reason you may recognize these files as the core RDO files.

            File          Description          Installed   Registered  Directory
            -------------------------------------------------------------------
            
            MSRDO20.dll  Remote Database       Shared          Yes     System32
                         Objects 2.0
            RDOCURS.dll  Batch Client Cursor   Companion       No*     System32
                         Library               to MSRDO20.DLL
          
      								

   * Rdocurs.dll is not a COM server (it doesn't export DllRegisterServer) so it is not registered. The Daosetup.rtf is incorrect and Regsrv32.exe should not be run against Rdocurs.dll.
3. Installation
   The following sections provide information on using the installation procedure.
   
   
   1. Check if files are in use.
      The first step in the installation procedure is to see if programs that are using any files you may be installing are running. If they are you may need to abort the installation and request the user to close other applications before installing DAO.
   2. Copy the files.
      Copy all files listed as DAO files (except the Dao350.dll and Dao2535.tlb), and all Microsoft Jet Engine core files (and application specific optional files) or ODBCDirect files (depending upon the needs of your application) to the system (system32 for Windows NT) directory (referred to in the charts above as the System32 directory). Per usual DLL standards, you need to copy with version checking to make sure a newer version of the file is not overwritten by your installation. All the DAO files contain appropriate version resources.
      
      Use the following procedure to copy Dao350.dll and Dao2535.tlb:
      
      
      1. For Windows NT (earlier version than 4.0), the DAO files always go into <windows>\MSAPPS\DAO. For example, c:\winnt35\msapps\DAO. For Windows 95 or Windows NT 4.0, the DAO directory is approximately c:\Program Files\Common Files\Microsoft Shared\DAO. The exact location varies if the user has a non-English version of Windows 95, which must read the location from the registry. Locate the following node in the registry:

                     HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
                
         										

         and retrieve the value of the key named CommonFilesDir.
      2. If this registry key does not exist, then create it and set the value to:

                     \Program Files\Common Files
                
         										

         Make sure to use the correct drive letter.
      3. After you have the value of the key, which will typically be:

                     c:\Program Files\Common Files
                
         										

         then append "\Microsoft Shared\DAO" and use that as the destination location for the Dao350.dll and Dao2535.tlb.
      4. Copy Dao350.dll and Dao2535.tlb to this directory using version checking. This is the Directory referred to in the charts above as the DAO directory.
   3. Register the DLLs.
      After you copy all of the DLLs, you need to register them. You do this by calling the DLLRegisterServer entry point on each DLL if it exists. Note that because DAO requires Microsoft Jet before it can successfully register, the order of copying files given previously is important.
      
      Your setup program should use Regsvr32.exe or an equivalent call to execute the DLLRegisterServer within the following dlls (if they have been installed by step 3b): Dao350.dll, Msjet35.dll, Msrd2x35.dll, Msexcl35.dll, Mspdox35.dll, Msxbse35.dll, Msltus35.dll, Mstext35.dll, Msexch35.dll, Msrdo20.dll.
      
      Following are some special considerations you should keep in mind:
      
      
      • Dao350.dll needs to have Msvcrt40.dll and other required files on the computer before it can register. If DAO fails to register, check the version of MSVCRT40.DLL. Problems are typically seen under Windows 95 where the version should be 4.10.6038 (about 319K file).
      • Msrdo20.dll needs to have ODBC installed before it will register. Use the ODBC Installation program to install ODBC.
      • Msexch35.dll needs to have MAPI installed on your system before it can register.
   4. Update the file reference counts.
      Because DAO is shared by many programs, a count is kept of how many times the DLL has been installed. This allows uninstall programs to remove the file only when no other program needs it. This is the same for the Msrdo20.dll. The other files are never removed from the system.
      
      
      1. Under the following location, search for a key with the same name as the file you've installed:

             HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SharedDlls\ 
                
         										

      2. If the key exists, increment its value by one (it is a dword). If the key does not exist, you need to create a key that is the name of the file (including path) of type dword and give it a value of 1. A typical entry would be:

                  \\Program Files\\Common Files\\Microsoft Shared\\DAO
                     \\DAO350.DLL"=dword:00000001
                
         										

         (This example is in the export format used by regedit; you would only use single backslashes when creating the key.)
         
         Make sure you reference count both the Msrdo20.dll and the Dao350.dll.
4. Uninstall
   To conform with Windows 95 guidelines, programs must be able to uninstall themselves and remove any files and registry entries they create. Many setup toolkits, such as the provided InstallShield toolkit, provide this as "built-in" functionality. It is beyond the scope of this document to provide all the details of Windows 95 installation requirements, but here are the basic steps required to uninstall DAO. Note that only the shared components and their companion files will be removed. The installed system files will never be removed.
   
   The Dao350.dll and Dao2535.tlb will be removed only if the value of Dao350.dll's reference count key is 1. Otherwise the count is decremented and the file left in place. For example:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SharedDlls\ "C:\Program Files\Common Files\Microsoft Shared\DAO\DAO350.DLL"
   
   Before removing Dao350.dll, you need to call its entry point DLLUnregisterServer so that it can remove its entries from the registry. You can do this by using Regsvr32.exe with the -u option.
   
   The same rules apply for the Msrdo20.dll and it's companion file of Rdocurs.dll.