Question

Can I access a VistaDB database via ODBC or OleDB?

Answer

VistaDB is written entirely for .NET and supports the .NET standard data access API - ADO.NET.  Unfortunately, ODBC and OleDB are unmanaged API's that rely on raw buffer access and other things not available in .NET.  Therefore, VistaDB has no providers for ODBC or OleDB.

It is theoretically possible to write an adapter in C or C++ between ODBC/OleDB and ADO.NET however it would be inefficient due to the extensive translations back and forth between managed and unmanaged code.  

Many applications that support ODBC/OleDB for database access also support ADO.NET.  If that option is available you should be able to use it by registering VistaDB as an ADO.NET provider for the current process.  For details on how to register VistaDB as an ADO.NET provider, see Deploying VistaDB with your Application.