ef update without select

update.cs

// ef
[Fact]
public async Task Test()
{
  var agent = new Agent()
  {
    Id = 9,
    Name = "new2"
  };
  _db.Agents.Attach(agent);
  _db.Entry(agent).Property(r => r.Name).IsModified = true;
  _db.SaveChanges();
}

// ef core
[Fact]
public async Task Test()
{
  var agent = new Agent()
  {
    Id = 9,
    Name = "new2"
  };
  _db.Entry(agent).Property(r => r.Name).IsModified = true;
  _db.SaveChanges();
}