System.DllNotFoundException on Mono SQLite

Question

I've been trying to figure this out lately. It is working on my Windows machine, where I got SQLite from NuGet, but...

When I put System.Data.SQLite.dll and SQLite.Interop.dll straight from my Windows machine into Linux server it says that SQLite.Interop.dll is not found, but I am sure I see it next right to executable.

Then I tried to compile System.Data.SQLite.dll with /p:UseInteropDll=false, but with no luck. This time it says that System.Data.SQLite.dll is not found.

What is this "not found" mystery?

Answer 1

No code changes necessary. You can build it yourself.

1. apt-get install build-essentials unzip
2. Download the SQLITE source code - you want the full source code. Currently called sqlite-netFx-full-source-1.0.104.0.zip.
3. unzip and cd Source,
4. chmod +x the compile-interop-assembly-release.sh build shell script, then run it ./compile-interop-assembly-release.sh. - It'll build an .so file in the ../bin directory.
5. Copy this .so file to the directory that has your application in
6. Run your application as normal.
7. Note: Ensure that your SQLite database and the directory it's inside of are writable by the user you're trying to run as.

Answer 2

Use Mono.Data.SQLite.dll on Linux. Take a look at the Mono manual to using SQLite on Linux or build the System.Data.SQLite.dll on Mono.

You can also map the DLL:

<configuration>
  <dllmap dll="sqlite" target="libsqlite.so.0" os="linux"/>
  <dllmap dll="sqlite" target="libsqlite.0.dylib" os="osx"/>
  <dllmap dll="sqlite3" target="libsqlite3.so.0" os="linux"/>
  <dllmap dll="sqlite3" target="libsqlite3.0.dylib" os="osx"/>
</configuration>

Answer 3

I started the development in Windows, but then moved the application to Mono (Ubuntu 14), which is where the SQLite provider failed to load as OP described.

I had to recompile the System.Data.SQLite.dll using the following command:

MSBuild System.Data.SQLite.2012.csproj /t:Rebuild /p:UseInteropDll=false /p:UseSqliteStandard=true 

However, after this I've got the following exception:

The provider did not return a ProviderManifest instance. Method System.Data.SQLite.UnsafeNativeMethods:GetSettingValue (string,string)' is inaccessible from methodSystem.Data.SQLite.EF6.SQLiteProviderManifest:GetProviderManifestToken (string)'

To fix this, I had to recompile the System.Data.SQLite.EF6.dll using the following command:

MSBuild System.Data.SQLite.EF6.2012.csproj /t:Rebuild /p:UseInteropDll=false /p:UseSqliteStandard=true

After copying all of the generated files to Mono project's bin directory, everything worked.

The SQLite provider source code version I had used was 1.0.98.1.

Hope this saves someone a lot of time...