32 bit oracle client in 64 bit application

[wesbird]

Hi,  

Is this possible, create a .Net 3.5 Dll(A.dll), reference to Oracle 11g 32 bit client Oracle.DataAccess.dll. this dll will be used in another dll(B.dll), which load in AutoCAD 64 bit application. 32 bit version of AutoCAD is not allowed to install on Windows 7 64 bit.   Right now I set my B.dll as 'Any CPU', and A.dll as 'Any CPU' as well.   Do I have to use 64 bit oracle client in my A.dll? if not, how I can make it works? 

Thank you

Wes

[StephenPreston · Accepted solution]

You can't load any 32-bit DLL into a 64-bit process space (and vice versa). So if the only Oracle driver DLL you have is 32-bit, then you'd have to do something like host that in a 32-bit standalone executable, and expose an interface (e.g. COM) from the executable that your 64-bit DLL can access.