IDesignTimeDbContextFactory
EntityFramework Core - Add an implementation of IDesignTimeDbContextFactory - Multiple DbContext's
Introduction We already talked about problem when Entity Framework Core tooling requires you to implement IDesignTimeDbContextFactory - check out this post. It gets interesting when you have more than one DbContext in your application and you want to add another implementation of IDesignTimeDbContextFactory, without repeating the code and making sure that EF Core tooling picks the right one.
EntityFramework Core - Add an implementation of IDesignTimeDbContextFactory
Problem Your DbContext in a separate project - class library project. You are trying to add new migration and update database, and you are running into this error: Unable to create an object of type ‘CodingBlastDbContext’. Add an implementation of ‘IDesignTimeDbContextFactory’ to the project, or see https://go.microsoft.com/fwlink/?linkid=851728 for additional patterns supported at design time.