code: func (au *AuthUser) Insert(db XODB) error {
  	var err error
  
  	// if already exist, bail
  	if au._exists {
  		return errors.New("insert failed: already exists")
  	}
  
  	// sql insert query, primary key provided by autoincrement
  	const sqlstr = `INSERT INTO auth_user (` +
  		`password, last_login, is_superuser, first_name, last_name, email, is_staff, is_active, date_joined, username` +
  		`) VALUES (` +
  		`?, ?, ?, ?, ?, ?, ?, ?, ?, ?` +
  		`)`
  
  	// run query
  	XOLog(sqlstr, au.Password, au.LastLogin, au.IsSuperuser, au.FirstName, au.LastName, au.Email, au.IsStaff, au.IsActive, au.DateJoined, au.Username)
  	res, err := db.Exec(sqlstr, au.Password, au.LastLogin, au.IsSuperuser, au.FirstName, au.LastName, au.Email, au.IsStaff, au.IsActive, au.DateJoined, au.Username)
  	if err != nil {
  		return err
  	}
  
  	// retrieve id
  	id, err := res.LastInsertId()
  	if err != nil {
  		return err
  	}
  
  	// set primary key and existence
  	au.ID = int(id)
  	au._exists = true
  
  	return nil
  }
docs: // Insert inserts the AuthUser to the database.