EF Core In-Memory Database Provider
This database provider allows Entity Framework Core to be used with an in-memory database. This can be useful for testing, although the SQLite provider in in-memory mode may be a more appropriate test replacement for relational databases. The provider is maintained as part of the Entity Framework Core Project.
Install the Microsoft.EntityFrameworkCore.InMemory NuGet package.
The following resources will help you get started with this provider.
Supported Database Engines
In-process memory database (designed for testing purposes only)