Microsoft.AspNetCore Version="1.1.2"
Microsoft.AspNetCore.Mvc Version="1.1.3"
Microsoft.Extensions.Logging.Debug Version="1.1.2"
Microsoft.EntityFrameworkCore.Design Version="1.1.1"
Microsoft.EntityFrameworkCore.SqlServer Version="1.1.1"
Microsoft.EntityFrameworkCore.SqlServer.Design Version="1.1.1"
Pomelo.EntityFrameworkCore.MySql Version="1.1.1"
Pomelo.EntityFrameworkCore.MySql.Design Version="1.1.1"

public class UserItem
{
    public long Id { get; set; }

    [MaxLength(32)]
    public string Username { get; set; }

    [MaxLength(256)]
    public string Password { get; set; } //Hashed Value

    public override bool Equals(object obj){
        if(obj is UserItem){
            return ((UserItem)obj).Id == this.Id;
        }
        return false;
    }

    public virtual ICollection<ConnectionItem> ConnectionItems { get; set; }
}

public class ConnectionItem
{
    public long Id { get; set; }

    public long UserRefID { get; set; }

    [ForeignKey("UserRefID")]
    public virtual UserItem User{ get; set; }

    [MaxLength(32)]
    public string TargetName { get; set; }

    [MaxLength(18)]
    public string TargetAddress {get; set; }
}

public class UserContext : DbContext
{
    public string ConnectionString{get; set;}
    public UserContext(DbContextOptions<UserContext> options) : base(options)
    {
    }

    public DbSet<UserItem> UserItems { get; set; }
}

public class ConnectionContext : DbContext
{
    public string ConnectionString{get; set;}
    public ConnectionContext(DbContextOptions<ConnectionContext> options) : base(options)
    {
    }

    public DbSet<ConnectionItem> ConnectionItems { get; set; }

}

public class Startup
{
    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
            .AddEnvironmentVariables();
        Configuration = builder.Build();
    }
    public IConfigurationRoot Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        var connection = Configuration["ConnectionStrings:MySQLConnectionString"];
        services.AddDbContext<UserContext>(opt => opt.UseMySql(connection)).AddDbContext<ConexaoContext>(opt => opt.UseMySql(connection));
        // Add framework services.
        services.AddMvc();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, UserContext uContext, ConexaoContext cContext)
    {
        app.UseMvc();
        InicializaBD.Initialize(uContext);
        InicializaBD.Initialize(cContext);
    }
}

public static class InicializaBD
{
    public static void Initialize(DbContext context)
    {
        context.Database.EnsureCreated();
        context.SaveChanges();
    }
}

+-------------------+
| Tables_in_arduino |
+-------------------+
| ConnectionItem    |
| UserItems         |
+-------------------+