Add an implementation of 'IDesignTimeDbContextFactory' to the project error while creating a migration step in .NET core 2.0

Question

I had a .NET core 1.0 webapp working fine. I had to upgrade to .NET Core 2.0. I also had to add a migration step for my SQLite database.

If I launch this command:

Answer 1

A possible solution to IDesignTimeDbContextFactory<> problem is the DBContext discovery/launch during the add-migration process. Add migrations needs to get a context. If it cant, this error is thrown. This can happen if you do not have a public parameter-less DBContext. So a solution is to Add a public Parameter-less constructor to your context.

public  class SomeDbContext: DbContext
{
    // this PUBLIC constructor  is required for Migration tool
    public SomeDbContext()
    {

    }
  // the model...
    public DbSet PocoBlas { get; set; }
    ....
 }

You can have a special version of your DBContext in a separate project .netCore console project for migration code generation purposes.