Architecture mismatch exception on connecting Visual Studio to Virtuoso 7.1 via ODBC DSN

Question

I know similar questions have been answered before, but I can't seem to clear my particular problem. The architecture mismatch exception is prompted when Db-driver and VS-project have different platform targets (32, 64 bit). So far so good.

First thing I tried: I changed my platform targets for my whole solution to 32 and after that to 64 bit. -> same error in both cases (I'm not sure under which circumstances VS considers a project to be of a specific architecture, though. Maybe someone can elaborate on this point...)

Now I focused on the driver and DSN for Virtuoso 7.1. Following the instructions for installing of the open source version of Virtuoso (link), I registered the driver in /lib using 'regsvr32 virtodbc.dll'. This promptly added it as a 32-bit Driver (visible when using the system32/odbcad32.exe). Using this driver in a DSN provided the architecture mismatch.

I tried to register the same dll as a 64 bit driver using the 64 bit version of regsvr32 without success. Since I can not add a suitable 64-bit DSN I would be content in using the 32-bit target cpu. As described the seemingly 32-bit versions of the virtodbc.dll are causing a architecture mismatch under any target platform configuration in VS.

I even installed the Client Connectivity Kit (link) which claim to provide only 64-bit drivers. Only to find out that the automatically installed drivers and DSN are also featuring as 32-bit drivers (meaning: they are only visible when using the 32-bit version of odbcad32.exe and not the 64-bit version)

I'm not sure where the problem lies (VS or Virtuoso drivers) and I would be thankful for your suggestions.

Answer 1

I think, you could try to install 32-bit ODBC driver from Virtuoso 6.4 Client Connectivity Kit.

p.s.

• 64-bit ODBC app requires 64-bit ODBC driver (and 64-bit ODBC driver manager)
• 32-bit ODBC app requires 32-bit ODBC driver (and 32-bit ODBC driver manager)

You can not mix them.

Answer 2

I am not quite sure I understand what your problem was or is ?

What is the bit'ness of your Visual Studio installation i.e. 32 or 64 bit ?

system32/odbcad32.exe is the 64bit ODBC Driver Manager despite the "system32" reference, which is a historic folder Microsoft retained from the 32 bit Windows days, placing the actual 32bit binaries on a 64bit system in sysWOW64 folder.

To make things even worse in the last 64bit Visual Studio I used the development environment is actually 32bit and the deployment is 64 bit, requiring a 32 & 64 bit driver for development and deployment, see http://wikis.openlinksw.com/dataspace/owiki/wiki/UdaWikiWeb/MsSqlOn64bitWin

As Virtuoso 7 is only available in 64bit form and the Virtuoso 6 ODBC Drivers (and data access client in general) are compatible with Virtuoso 7 server, you can install the Virtuoso 6 commercial (as Sergei mentioned) or open source (http://bit.ly/1A3mCje) 32 & 64 bit ODBC Drivers and VS should then just work as it has one for development and one for deployment.