Derby sequence with Hibernate

Derby sequence

CREATE SEQUENCE MD_USER_SEQ
AS INT
START WITH 1;


Hibernate mapping to get User_id from sequence

<id name="userId" type="integer" column="USER_ID" >
<generator class="sequence">
<param name="sequence">MD_USER_SEQ</param>
</generator>
</id>

[update:]
after all there is an issue with DerbyDialect of hibernate.
So need the following fix. 



package entity;


import org.hibernate.dialect.DerbyDialect;


/**
 *
 * @author Srinath
 */
public class MyDerbyDialect extends DerbyDialect{


    @Override
public String getSequenceNextValString(String sequenceName) {
        return "values next value for " + sequenceName;
}
}


Then in hibernate config

  <property name="hibernate.dialect">entity.MyDerbyDialect</property>

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Derby sequence with Hibernate

Hibernate querying and iteration using JSTL

1.If a query return a single raw with data from mulitple tables
(unique result with mulitple objects in-hibernate),
it returns array of Entity Objects.
A[0]
A[n]
....

2.If a query return multiple raws with data from mulitple tabels
it return List of Array objects.
L[0] ---
|+--- A[0]...A[m]
L[n] ---
|+--- A[0]...A[m]
.....

Code for situation 1

   SQLQuery query = session.createSQLQuery(sql);
   query.addEntity("person", Person.class);
   query.addEntity("specializations", Entity.Specializations.class);
       
    Object obj =  query.uniqueResult();
  // obj is an array
  //A[0] will be a "person" and A[1] will be a "specializations" Object

View using JSTL

${objectArray[0].salutationText}. ${objectArray[0].nameWithInitials}
${objectArray[1].specializationText}

Code for situation 2

SQLQuery query = session.createSQLQuery(sql);
query.addEntity("session", Entity.Session.class);
query.addEntity("person", Person.class);

     list = query.list();
    // this return List of Arrays 
    // where L[n]  A[0] -- "session" , A[1] -- "person"

Iterate using JSTL

      ${p[0].sessionId}
      ${p[0].sessionDate}
      ${p[1].name}
      ${p[1].address}

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Hibernate querying and iteration using JSTL