Hibernate Insert if record does not exist

Question

How can I do this with Hibernate - If record does not exists insert it.

I have the following columns

Id (Primary Key), Ticker Symbol, Ticker Name, Industry, Sector, LastUpdate

I would like to check the records at Ticker Symbol Column if the string exist don't do anything if it does not exist then insert a new row with Id, Ticker Symbol, Ticker Name, Industry, Sector and Update Date (today's date).

I have gone as far as creating a new Table with the code below.

//Hibernate Create a Session Factory    
 SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();         
 for (int i = 0; i < Bloomberg.getTickerSymbol().size(); i++){

            //Hibernate to store Stock Tickers Data     
        tickerInfo.setTickerSymbol(Bloomberg.getTickerSymbol().get(i)); //Symbol
        tickerInfo.setTickerName(Bloomberg.getTickerName().get(i)); //Name
        tickerInfo.setTickerSector(Bloomberg.getTickerSector().get(i)); //Sector
        tickerInfo.setTickerIndustry(Bloomberg.getTickerIndustry().get(i)); //Industry
        tickerInfo.setTickerLastUpdate(Calendar.getInstance().getTime()); //Update Date

        org.hibernate.Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.saveOrUpdate(tickerInfo);
        session.getTransaction().commit();
        session.close();
}

Answer 1

 //Hibernate Create a Session Factory    
 SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();         
for (int i = 0; i < Bloomberg.getTickerSymbol().size(); i++){

        //Hibernate to store Stock Tickers Data     
    tickerInfo.setTickerSymbol(Bloomberg.getTickerSymbol().get(i)); //Symbol
    tickerInfo.setTickerName(Bloomberg.getTickerName().get(i)); //Name
    tickerInfo.setTickerSector(Bloomberg.getTickerSector().get(i)); //Sector
    tickerInfo.setTickerIndustry(Bloomberg.getTickerIndustry().get(i)); //Industry
    tickerInfo.setTickerLastUpdate(Calendar.getInstance().getTime()); //Update Date

    org.hibernate.Session session = sessionFactory.openSession();
    List tickerInfos = session.createCriteria(TickerInfo.class).add(Restrictions.eq("tickerSymbol", Bloomberg.getTickerSymbol().get(i))).list();
   if(tickerInfos.size()<1){
         session.beginTransaction(); 
         session.saveOrUpdate(tickerInfo);
         session.getTransaction().commit();
   }
 }
session.close();

Answer 2

An option could be to create a unique constraint in your database, attempt the update, and catch the exception if the constraint is violated.

A better approach might be a mix this with a local cache of known added ticker symbols (assuming symbols are never removed), which should cut down to the amount of database calls being made.