Posts filed under 'Programming'
I’m currently researching ways to move my main MS Access application from a simple local network client/backend setup to a global, multiple remote sites configuration using SQL Server.
One of the challenges is to upsize the current MS Access 2007 backend database to SQL Server 2008.
If you try it from Access itself using the Upsizing Wizard, you may end up getting this error message:
The Upsizing Wizard only works with Microsoft SQL Server (Versions 6.50 SP5 or higher). Please log in to a SQL Server data source.
After spending some time fiddling around with SQL Server settings I couldn’t understand why I was still getting this error.
Turns out that the upsizing wizard is apparently sensitive to the version of SQL Server you’re using and it doesn’t consider SQL Server v10 (2008) as being later than v6.50…
This issue is in fact a blessing.
Microsoft provides a migration tool for upsizing MS Access database to SQL Server 2008 that’s orders of magnitude better than anything the basic wizard can do: the SQL Migration Assistant for Access, or SSMA.
SSMA lets you take a bunch of Access databases and move the tables and queries you choose to SQL Server, automatically linking them in your original database if you want.
It’s not just a one-off thing either: SSMA keeps track of the objects that where transferred and allows you to synchronise both schema and data as often as you need.
So here you are: do not use the basic MS Access Upsizing Wizard, download and use SSMA instead.
Strange COM Error
While SSMA works perfectly fine on my Windows 2008 x64 laptop, on my main Windows XP desktop it throws an exception when trying to load an Access database:
Unable to cast COM object of type ‘Microsoft.Office.Interop.Access.Dao.DBEngineClass’ to interface type ‘Microsoft.Office.Interop.Access.Dao._DBEngine’
… {00000021-0000-0010-8000-00AA006D2EA4}…
It was a COM error saying that the library for DAO couldn’t be loaded.
I couldn’t find any relevant information on the web.
After a while, I had a look at the DAO driver in
C:\Program Files\Common Files\Microsoft Shared\DAO\dao360.dll
and I noticed that the filename was in blue: that reminded me that I had set compression on the filesystem.
I disabled compression for the file and, magically, SSMA worked again…
Moral of the story: be careful about compressing your filesystem, some registered libraries and system files may work in unpredictable ways…
References
Updates
- 17MAR2009: Added section on the strange COM error.
- 14MAR2009 : Added links to Tony’s Access MVP website.
- 05JAN2009 : Original publication.
March 17th, 2009
(Updated Wednesday 30JAN2009.) Developing applications that manipulate OpenOffice documents has always been rather tricky; not very difficult, but just tricky to get right.
With OpenOffice 3, things got trickier and applications that used to work will now fail.
I’ve just spend nearly a day trying to get a mail-merge application I built to work again with the new version of OO.
Changes and limitations
Developing .Net applications with OpenOffice 3 now requires that the .Net framework 3.5 be installed.
Only one version of OpenOffice/StarOffice must be installed.
Getting the CLI assemblies in your project
OpenOffice used to ship with a bunch of CLI DLLs for manipulating Open Documents from .Net.
With OpenOffice version 3, these DLLs are directly installed in the GAC and not available in the Program installation folder any longer, making them unavailable when you need to add them as references to your Visual Studio project.
The trick is to extract the DLLs from the installation CAB, then reference those and make sure you exclude them in your setup file so only the latest version installed on the user’s computer’s GAC will get used.
- Open the installation folder where the installation files are extracted (usually left on your desktop under a folder like
OpenOffice.org 3.0 (en-US) Installation Files during the OO installation process.
- Open the
openofficeorg1.cab file (using a utility like 7zip if necessary) and extract the files matching cli_*.dl.
- Add the ones you need to your VS Project’s references and make sure the properties of these references have their Copy Local and Specific Version properties set to false.
- If you have a setup project that added these references to the list of files, right-click each of them and select Exclude to make sure they won’t be packaged.
The reason for not deploying the DLLs is that they are very specific to a given OpenOffice version and the latest assemblies relevant to the user’s OpenOffice installation will already be deployed to the target machine’s GAC.
When .Net loads assemblies, if they are not included in the path of the application being launched, they will be loaded from the GAC if they can be found there.
Path and environment setup
Before being able to call OpenOffice from your application you now must set your application’s environment variables to the correct paths so the assemblies can find the actual OpenOffice library and program files.
Basically, you need to add to your PATH the path to the folder where the UNO java libraries reside.
You also need to add a UNO_PATH environment variable that points to the program folder of OpenOffice.
Basically, before any call to OpenOffice functions you must:
- Append to
PATH something like C:\Program Files\OpenOffice.org 3\URE\bin.
- Create a
UNO_PATH variable set to C:\Program Files\OpenOffice.org 3\program.
Because there is no guarantee that these paths will not change or are valid for all systems you must get them from specific keys located in the Registry:
PATH is appended with the vaue of HKLM\SOFTWARE\OpenOffice.org\Layers\URE\1\UREINSTALLLOCATION to which you must append the bin directory.UNO_PATH is set to the content of the HKLM\SOFTWARE\OpenOffice.org\UNO\InstallPath key.
See the C# and VB.Net code below for working examples.
Special Considerations for x64 systems
My development machine runs Windows Server 2008 x64 and I’ve ran into some specific issues that you’re likely to encounter when deploying to a 64 bits OS.
OpenOffice is 32 bits only
That means that your .Net project must be set to target x86 systems only:
Open your Solution’s Configuration Manager and under Active solution platform click New… then:
Make sure you repeat this for both the Debug and Release configurations.
Registry keys are elsewhere
32 bit applications see their registry keys normally expected under:
HKEY_LOCAL_MACHINE\Software moved to:
HKEY_LOCAL_MACHINE\Software\Wow6432Node instead.
This of course creates issues when you’re trying to read a registry key that’s not where it should be…
The Code
The code below will allow you to correctly connect to OpenOffice 3 under 32 or 64 bit systems.
It reads the registry to find the proper paths and appends the PATH and creates the UNO_PATH environment variables expected by the the bootstrapper to find the OpenOffice program and libraries.
The code is built upon information and a test program made available by Marten Feldtmann on his blog (more information, in English, is available on OOoForum ).
Please let me know if this works for you or if you have any corrections.
In VB.Net:
Updates
07MAY2009 -- Added reference link to OOo documentation.
03DEC2008 -- Added VB.Net translation. Thanks to Stefan for suggesting it.
30JAN2009 -- Added reference to Aleksandr Sazonov’s article on CodeProject (thanks for the the article).
References
November 6th, 2008
There are times when the coexistence of 64 and 32 bit code on the same machine can cause all sorts of seemingly strange issues.
One of them just occurred to me while trying to run the ASPx demos from Developer Express, my main provider of .Net components (the best supplier I’ve ever been able to find).
I was getting the following error:
The ‘Microsoft.Jet.OLEDB.4.0′ provider is not registered on the local machine:
It may look otherwise, but this error is generally due to either of two thing:
- you don’t have Office 2007 Jet drivers installed
- or you are running a 32 bit application in a default x64 environment.
The first issue is easy to solve, just download the 2007 Office System Driver from Microsoft.
For the second one, the fix is easy enough:
- For Windows 2008: Navigate to Server Manager > Roles > Web Server (IIS) > Internet Information Services (IIS) Manager, then look under your machine name > Application Pool.
- For Windows 7: Navigate to Programs > Administrative Tools > Internet Information Services (IIS) Manager, then look under your machine name > Application Pool.
Under there you can call the DefaultAppPool’s advanced settings to change Enable 32-Bits Applications to True:
You may have to restart the service for it to take effect but it should work.
References
Updates
- 03APR2010: Added instructions for Windows 7
- 12FEB2009: Added reference to Scott’s article.
- 28OCT2008: Original version
October 28th, 2008
My trusty old gigantic Sony Vaio is about 4 years old. It served me well and still works but it’s about to become my main development machine for the next couple of months and I can’t afford to have it die on me during that time.
It was time to get something as gigantic and more up-to-date in terms of technology.
I use VMware on my main desktop to keep multiple OS setups that match typical configurations of my customer’s machines.
This allows me to test my software before deployment and make sure everything works as expected.
It saved me many times from strange bugs and I would consider these final tests to be a mandatory step before deployment.
My old trusty vaio would be hard pressed to run any of these without slowing down to a crawl.
I looked at some possible replacements. Initially I checked Lenovo’s offerings but they don’t seem to offer anything in large screen size (WUXGA 1920×1200) (Note, actually, they have, but not really for me).
Dito for Dell, not counting their humongous XPS M1730 luggable gaming machine that was wayyy over the top as a work computer, not to mention probably heavier than its volume in pure gold.
On a hint from a friend I checked out Apple’s online store and saw they had a nice Macbook Pro configuration. I went to check it out in the retail store close to my office and they had that exact specification in stock, so, in what must have been the highest rated expense/time-to-think ratio of any decision I ever took, well, I bought it…
The spec, some bragging rights:
- Macbook Pro 17″
- Core Duo T9500 2.6GHz processor
- nVidia 8600M GT 512MB graphics card
- 200GB 7200rpm drive
- Kingston 4GB DDR2 667MHz RAM
- Hi Resolution 17″ 1920×1200 glossy screen
It’s a very nice machine, Apple knows how to make nice hardware, there is no question there.
OSX has some cool features, some of them still a bit foreign to me and some minor annoyances are creeping up, like Thunderbird’s not picking up my system date and time settings and displaying the date in the wrong format (a pet peeve of me), probably not Apple’s fault but annoying nonetheless.
So far so good and while I don’t mind using OSX for my browsing, email and creative stuff, that machine is meant to be running Windows Server 2008 x64 as a development platform.
Why Windows Server 2008 x64?
Well, it has some excellent features, a smaller footprint than Vista, all the aero eye candy, is apparently noticeably faster than Vista and has none of the nagging security prompt (you are considered administrator though, so keeping safe is entirely up to you).
The 64 bit version can also address the full 4GB of RAM without limitation and all server features are optionally installable.
By default, the installation is actually pretty minimal and you have to set services and options to get Windows configured as a proper workstation. It is after all, meant to be a server.
Oh, I almost forgot that there is also support for HyperV, although you must make sure you download the right version (if you list all available downloads in your MSDN subscription, you’ll see some that are explicitly without that technology).
Installing Windows Server 2008 x64 is remarkably easy.
- Get your hands on the ISO from your MSDN subscription or an install DVD from somewhere else (like a MS event, or even as a free 240 days download from Microsoft).
- You’ll need to repackage the ISO as it won’t work properly (something to do with non-standard file naming options).
It’s fairly easy if you follow the instructions from Jowie’s website (cached version): you can get the ImgBurn software for free as well, which is a good find in itself. It should’t take more than 30 minutes to repackage the DVD.
- In OSX, go to Applications > Utilities > Boot camp and follow the instructions on screen.
You will be able to resize the default partition by just moving the slider. I left 60GB for OSX and allocated the rest to Windows. The good thing is that OSX can read Windows partitions, so you can always store data there. Windows however, can’t read the HFS+ mac file system, although there are some third-party tools that can do it [1] [2] [3].
- Insert your repackaged DVD and Bootcamp will have rebooted the machine.
After a few minutes of blank screen (and no HDD activity light to let you know something is happening), windows setup launches.
- You will be then prompted with the choice of partition to install to.
Select the one named BOOTCAMP, then click the advanced options button and click format.
From there one, windows will install everything, then reboot, then carry on installing, then reboot one last time.
- Now, insert your OSX recovery CD 1. It should automatically launch the driver installation.
Once done, you’ll reboot to a nice, full-resolution windows prompt.
- All drivers will have been installed correctly except the one for Bluetooth. To easily solve that issue, just go to Spencer Harbar’s website and read how to install the Bluetooth drivers. Takes 5 minutes tops.
The final touches
A few notes to quickly get things running as expected.
- Get the most of your configuration by following the list of tweaks from Vijayshinva Karnure from Microsoft India.
- There are more tweaks, and even more tweaks available as well (don’t forget to enable Superfetch).
- Microsoft has a whole KB entry on enabling user experience.
- In the Control Panel > System > Advanced System Settings > Advanced > Settings > Advanced > Processor scheduling, set to Programs instead of Background services.
- Activate your copy of Windows using Control Panel > System.
I was getting an error code 0x8007232B DNS name does not exist error. To force activation, just click on the Change Product Key button and re-enter the same key you used during install.
Windows will activate straight away.
- When booting your Macbook, press the Option key and you will be presented a list of boot choices.
- You can check on Apple’s Bootcamp webpage other information about how to use the track pad, keyboard layouts etc,
References
August 31st, 2008
Years ago I did a small utility to convert DWG or DXF files into a vector-graphic, zoomable, SVG preview.
The Linux command-line utility was used in a larger drawing management application that I had built before I left that company for greener pastures.
The Linux server-based application would scan the vast (100,000s of CAD drawings) and, depending on their format, attempt to create thumbnails and extract textual information from them and populate a database so we could easily find related drawings through a simple web-interface.
The software would present thumbnails of the drawings; when the drawing was in DWG or DXF format, the thumbnail would be an SVG vector representation of the original drawing instead of an image. That made the preview much more useful as you could zoom in and still retain enough detail to ascertain if the drawings was actually what you were looking for.
Other file formats (TIFF, HPGL plots, etc) were transformed into PNG image previews that were saved into 2 size: a small thumbnail, good enough to be displayed in a list, and a larger one that would show more details.
The server software was written in Perl, with some of the converters in C. Every night, the server would go through the whole tree of drawings on the filesystem, looking for drawings it hadn’t seen before and it would pass them to the appropriate plug-in for extracting text -where possible- and create thumbnails.
Memories of fun projects…
Download links:
July 18th, 2008
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I couldn’t find any relevant information on the web.
