Writing to KDB using qJava

I'm not very good with KDB (in case the question sounds silly). I am trying to use kdb (disk not memory) to load all my data from the database. I already asked a question about upserts and I figured out how to take off from console and save to disk

q)dsPricing:([id:`int$(); date:`date$()] open:`float$();close:`float$();high:`float$();low:`float$();volume:`int$())
q)dsPricing:([id:`int$(); date:`date$()] open:`float$();close:`float$();high:`float$();low:`float$();volume:`int$())
q)`dsPricing insert(123;2003.03.23;1.0;3.0;4.0;2.0;1000)
q)`dsPricing insert(123;2003.03.24;1.0;3.0;4.0;2.0;2000)
q)save `:dsPricing
q)`:dsPricing upsert(123;2003.03.25;1.0;3.0;4.0;2.0;1500)

      

        
        
        
      

    

Now I am trying to do it in Java and have the following code

public class LoadDS {
SqlSession session;
private DataStreamMapper mapper ;
public static void main(String args[]){
     final QConnection q = new QBasicConnection(args.length >= 1 ? args[0] : "localhost", args.length >= 2 ? Integer.parseInt(args[1]) : 5001, "user",
                "pwd");

     LoadDS l=new LoadDS();

      l.session = MyBatisConnectionFactory.getSqlSessionFactory("SMALLS").openSession();
      l.mapper = l.session.getMapper(DataStreamMapper.class);
      List<DataStream> prices = l.mapper.selectHistoricalPrices(1);
      try {
          q.open();
        q.sync("upsert", "'dsPricing", l.getData(prices));
    } catch (QException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

// dsPricing:([id:`int$(); date:`date$()] open:`float$();close:`float$();high:`float$();low:`float$();volume:`int$())
 private Object[] getData(List<DataStream> prices) {

        final Object[] data = new Object[] {new int[prices.size()], new QDate[prices.size()],
                                            new float[prices.size()], new float[prices.size()],
                                            new float[prices.size()],new float[prices.size()],
                                            new int[prices.size()]

        };
        for ( int i = 0; i < prices.size(); i++ ) {

             ((int[]) data[0])[i] = prices.get(i).getInfoCode();
            ((QDate[]) data[1])[i] = new QDate(prices.get(i).getMarketDate());
            ((float[]) data[2])[i] = (float)prices.get(i).getOpen_();
            ((float[]) data[3])[i] = (float)prices.get(i).getClose_();
            ((float[]) data[4])[i] = (float)prices.get(i).getHigh();
            ((float[]) data[5])[i] = (float)prices.get(i).getLow();
            ((int[]) data[6])[i] = (int)prices.get(i).getVolume();
        }

        return data;
    }

      

        
        
        
      

    

}

Can anyone tell me what I am doing wrong? No data is saved and I tried several options. I'd rather just load the data from SQL and save it to disk for bootstrapping.