code: func (dm *DjangoMigration) Insert(db XODB) error {
  	var err error
  
  	// if already exist, bail
  	if dm._exists {
  		return errors.New("insert failed: already exists")
  	}
  
  	// sql insert query, primary key provided by sequence
  	const sqlstr = `INSERT INTO public.django_migrations (` +
  		`app, name, applied` +
  		`) VALUES (` +
  		`$1, $2, $3` +
  		`) RETURNING id`
  
  	// run query
  	XOLog(sqlstr, dm.App, dm.Name, dm.Applied)
  	err = db.QueryRow(sqlstr, dm.App, dm.Name, dm.Applied).Scan(&dm.ID)
  	if err != nil {
  		return err
  	}
  
  	// set existence
  	dm._exists = true
  
  	return nil
  }
docs: // Insert inserts the DjangoMigration to the database.