composite key and Criteria API [Hibernate]

[prateek urmaliya]

Hi All,

I have a composite key with three columns (a,b,c) that I need to map,
I created a @Embeddable PK class

    
import javax.persistence.Column;
import javax.persistence.Embeddable;
 
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
 

@Embeddable
public class EmbeddablePK implements java.io.Serializable {
 
  private static final long serialVersionUID = 1L;
 
  // Fields
 
  private int a;
 
  private int b;
 
  private int c;
 
  
  @Column(name = "A", nullable = false)
  public int getA() {
    return a;
  }
 
  public void setA(int a) {
    this.a = a;
  }
 
  
  @Column(name = "B", nullable = false)
  public int getB() {
    return b;
  }
 
  public void setB(int b) {
    this.b = b;
  }
 
  
  @Column(name = "C", nullable = false)
  public int getC() {
    return c;
  }
 
  public void setC(int c) {
    this.c = c;
  }
 
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!(obj instanceof EmbeddablePK)) {
      return false;
    }
 
    final EmbeddablePK castOther = (EmbeddablePK) obj;
 
    return new EqualsBuilder().append(a, castOther.a).append(b, castOther.b).append(
        c, castOther.c).isEquals();
  }
 
  @Override
  public int hashCode() {
    return new HashCodeBuilder().append(a).append(b).append(c).toHashCode();
  }
}
 

and provided it as @EmbeddedId in the mapping class

import javax.persistence.AttributeOverride;
import javax.persistence.AttributeOverrides;
import javax.persistence.Column;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.Table;
 
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
 

 
@Entity
@Table(name = "TABLE_COMPOSITE")
public class TableComposite implements java.io.Serializable {
 
  private static final long serialVersionUID = 1L;
 
  // Fields
 
  private EmbeddablePK id;  
 
  private boolean active;  
 
  public TableComposite() {
  }
  
  @EmbeddedId
  @AttributeOverrides( { @AttributeOverride(name = "a", column = @Column(name = "A", nullable = false)),
    @AttributeOverride(name = "b", column = @Column(name = "B", nullable = false)),
    @AttributeOverride(name = "c", column = @Column(name = "C", nullable = false)) })
  public EmbeddablePK getId() {
    return this.id;
  }
 
  public void setId(EmbeddablePK id) {
    this.id = id;
  }  
 
  
  @Column(name = "IS_ACTIVE", nullable = false)
  public boolean isActive() {
    return this.active;
  } 
 
 
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!(obj instanceof TableComposite)) {
      return false;
    }
 
    final TableComposite castOther = (TableComposite) obj;
 
    return new EqualsBuilder().append(id, castOther.id).isEquals();
  }
 
  @Override
  public int hashCode() {
    return new HashCodeBuilder().append(id).toHashCode();
  }
 
}
    

I've tried few things but they are not working

    
        final Criteria crit = session.createCriteria(TableComposite.class);
 
        TableComposite comp = new TableComposite();
 
        EmbeddablePK id = new EmbeddablePK();
 
        id.setA(123);
        id.setB(456);
        
        comp.setId(id);        
 
        crit.add(Example.create(comp));                
        
        return crit.list();

(I also tried setting value of C but it didn't help)

Now I want something like SELECT * FROM TABLE_COMPOSITE WHERE A = ? AND B = ? using Criteria API

Please help.

[prateek urmaliya]

I tried something like

final Criteria crit = session.createCriteria(TableComposite.class)
                                     .createAlias("id", "id")
                                     .add(Restrictions.eq("id.a", 123))
                                     .add(Restrictions.eq("id.b", 456));

but I am getting

could not resolve property: a of: TableComposite

am I missing something here ?

[prateek urmaliya]

it's workin

I tried

final Criteria crit = session.createCriteria(TableComposite.class)
.add(Restrictions.eq("id.A", 123))
.add(Restrictions.eq("id.B", 456));

I was missing that though my field was a the getter was getA
Also I don't need alias as I am not joining anything
Thanks to my colleague DT

[Anu Sharma]

I have a Class Address with the composite key (personId, departmentId). I created a class PersonDepartmentId as below

import java.io.Serializable;

/**
 * These objects are composite ids for the Address class
 *
 */
public class PersonDepartmentId implements Serializable {

    /**
     * Comment for <code>serialVersionUID</code>
     */
    private static final long serialVersionUID = 1L;

    public PersonDepartmentId() {
        super();

    }

    
    /**
     * Primary key components
     */
    private Long personId;
    private Long departmentId;
    
    /**
     * Return the person component of the id
     * 
     * @return the person component of the id
     * @hibernate.property column="PERSON_ID"
     */
    public Long getPersonId(){
        return this.personId;
    }
    /**
     * Set the person component of the id
     * 
     * @param the person component of the id to be set
     */
    public void setPersonId(Long personId){
        this.personId = personId;
    }
    
    /**
     * Return the department component of the id
     * 
     * @return the department component of the id
     * @hibernate.property column="DEPARTMENT_ID"
     */
    public Long getDepartmentId(){
        return this.departmentId;
    }
    /**
     * Set the department component of the id
     * 
     * @param the department component of the id to be set
     */
    public void setDepartmentId(Long departmentId){
        this.departmentId = departmentId;
    }
    
    /**
     * Define a hash code method
     */
    public int hashCode() {
        return personId.hashCode() + 37 * departmentId.hashCode();
    }
    
    /**
     * Define an equals comparison method
     */
    public boolean equals(Object other){
        if (this == other) {
            return true;
        }
        
        if (other instanceof PersonDepartmentId) {
            PersonDepartmentId that = (PersonDepartmentId) other;
            return (this.personId.equals(that.getPersonId()) &&
                    this.departmentId.equals(that.getDepartmentId()));
        }
        return false;
    }
    
    /**
     * Define a toString method
     */
    public String toString(){
        StringBuffer str = new StringBuffer();
        str.append("PersonDepartmentId[");
        str.append(this.personId);
        str.append(",");
        str.append(this.departmentId);
        str.append("]");
        return str.toString();
    }
}

To search an address I used criteria

            Session session = super.getSession();
            Criteria criteria = session.createCriteria(Address.class)
                    .add(Restrictions.eq("personDepartmentId",personDepartmentId ));
            
            address = (Address)criteria.uniqueResult();

Where personDepartmentId is a reference to an object of type PersonDepartmentId.
Also, please note that the equals method of PersonDepartmentId has been overridden.

And this works....

[dayse rocha]

Alguém pode me explicar o que está errado no código abaixo?

public static void main(String[] args) throws Exception {
SessionFactory session = HibernateUtil.getSessionFactory();
Session sess = session.getCurrentSession();

Transaction tx = sess.beginTransaction();

CompoundKey key1 = new CompoundKey(500, 1001);
Accounts saving = new Accounts();
saving.setCompoundKey(key1);
saving.setAccountBalance(8500);

CompoundKey key2 = new CompoundKey(500, 2001);
Accounts checking = new Accounts();
checking.setCompoundKey(key2);
checking.setAccountBalance(8500);

sess.saveOrUpdate(saving);
sess.saveOrUpdate(checking);

Criteria crit = sess.createCriteria(Accounts.class).add(
Restrictions.eq("compoundKey.userId", new Integer(500)));
List accList = crit.list();
for(int i = 0; i < accList.size(); i++){
Accounts acc = (Accounts) accList.get(i);
System.out.println(acc.getAccountBalance());
}
tx.commit();

session.close();
}
-----------------------------------------------------------------------------------------------
package hibernate;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Accounts {
private CompoundKey compoundKey;
private int accountBalance;

@Id
public CompoundKey getCompoundKey() {
return compoundKey;
}
public void setCompoundKey(CompoundKey compoundKey) {
this.compoundKey = compoundKey;
}
public int getAccountBalance() {
return accountBalance;
}
public void setAccountBalance(int accountBalance) {
this.accountBalance = accountBalance;
}

}
-----------------------------------------------------------------------------------------------
package hibernate;

import java.io.Serializable;

import javax.persistence.Embeddable;
@Embeddable
public class CompoundKey implements Serializable{
private int userId;
private int accountId;

public CompoundKey(int userId, int accountId) {
super();
this.userId = userId;
this.accountId = accountId;
}

public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public int getAccountId() {
return accountId;
}
public void setAccountId(int accountId) {
this.accountId = accountId;
}

public CompoundKey() {
super();
}
}