Using 'System.Data.OleDb' on 'net472' throws 'TypeLoadException'

[lauxjpn]

@lauxjpn: I am not sure if the implementation is buggy or if I do something wrong, but when trying to load my database via oledb the version I provide with nuget gets ignored and I get the TypeLoadException from JetFactory. The call of Type.GetType(...) seems to be problematic, if I load the System.Data.OleDb via Assembly.Load(..) the correct one gets loaded, but Type.GetType(...) uses the default for my target framework (in this case net472). Should I open up a bug or is this my fault?

Originally posted by @xoniuqe in #34 (comment)

[lauxjpn]

@xoniuqe How are you referencing OleDb in the project file?
Is it like <PackageReference Include="System.Data.OleDb" Version="5.0.0" />

Originally posted by @ChrisJollyAU in #34 (comment)

[lauxjpn]

@ChrisJollyAU Yes I did. I will upload a demo project on my github. https://github.com/xoniuqe/Ef-Core-Jet-TypeLoadException

Originally posted by @xoniuqe in #34 (comment)

[lauxjpn]

@xoniuqe Do you specifically need the full .net framework? Changing your demo to use .net core 3.1 is a possible solution

Originally posted by @ChrisJollyAU in #34 (comment)

[lauxjpn]

@ChrisJollyAU I have dependencies to .net Framework assemblies which are not usable in .net core 3.1, so yes.

Originally posted by @xoniuqe in #34 (comment)

[lauxjpn]

@xoniuqe I tried adding a binding redirect but didnt work. I can see in the debug as it loads, it loads the correct version but at runtime the .net framework version keeps on getting picked.

Should probably open a issue specific for this

Originally posted by @ChrisJollyAU in #34 (comment)

[lauxjpn]

Here's the problem. The netstandard version includes all the OleDb classes whereas the .net framework version doesn't. It in turn references the normal System.Data

@lauxjpn The OleDb bug that was in the net core version, do you know if that was only in net core? If so on the full framework you can ignore the version check. Tried without the version check and it goes further but I do get a COM error when it tries to create the database using DAO

Originally posted by @ChrisJollyAU in #34 (comment)

[ChrisJollyAU]

@xoniuqe I tested my changes and it does work on your test project. It will just use the OleDb classes from the framework's System.Data rather than the nuget package. Also I would recommend changing your connection string to use ACE rather than Jet. Jet is quite old and only supports database formats up to around access 2003. Creating a new database will use DAO which will use the current access runtime installed. If you are using e.g the 2010 or 2016 runtime, it will be created in that format which is not supported when using the Jet connection string.

Should only need to change the Provider to Microsoft.ACE.OLEDB.12.0

Have it working in both x86 and x64

[xoniuqe]

@ChrisJollyAU Thank you for the fast work, unfortunalety I think I have to stick to the Jet driver because we currently have the requirement to work with the old database format. But I give it a try and will give you an update. But this has to wait until monday.