java - left join in hibernate using annotation -

i have 2 table follows

@entity @table (name="booking_basic") public class booking_basic {      @id     @generatedvalue     @column (name="booking_id")     private int booking_id;       @genericgenerator(name="foreign", strategy="foreign", parameters={@org.hibernate.annotations.parameter(name="property", value="organizer_basic")})     @column (name="org_id")     private int org_id;     @onetoone(fetch=fetchtype.eager, optional=true)     @primarykeyjoincolumn     @cascade({org.hibernate.annotations.cascadetype.save_update})        private organizer_basic organizer_basic;         .... 

another

@entity @table(name="organizer_basic") public class organizer_basic {    @id   @generatedvalue   @column(name="org_id")   private int org_id;    @column(name="name")   private string name;    @onetoone(cascade={javax.persistence.cascadetype.all}, fetch=fetchtype.lazy, mappedby="organizer_basic")   @joincolumn(name="org_id")     private booking_basic booking_basic;  ..... 

now organizers name based on booking id, if booking_basic have booking_id 1 , org_id = 15, access organizer name org_id 15.

        session session = hibernatesessionfactory.getsessionfactory().opensession();         transaction transaction = null;         try {           transaction = session.begintransaction();           query query = session.createquery("from booking_basic");           list<booking_basic> booking_basic = query.list();           for(booking_basic b : booking_basic)               system.out.print("booking type : " + b.getorganizer_basic().getname());           }           transaction.commit();         }         catch (exception e) {           e.printstacktrace();           transaction.rollback();         } 

but when try run it, it's giving me null pointer exception. body have idea, please me.

try this:

session.createquery("from booking_basic b left join b.organizer_basic o");