Jair Rillo Junior’s blog

Thanks, you saved me some headaches with this tip.

Thank you, you saved me many hours of work

Thank you for sharing !!! You saved me many hours !!!

Hi,
Could you please tell me , how to use full join with Hibernate+MySQL .
Thanks in advance.
Sridevi.

Thank you. You saved my time.

Thank you man, really nice and short way to learn hibernate criteria specification…great

I apply Criteriaspecification left join process-how to check the condition(ex:in sql query(left join tablename a on(a.staus=’A')) that process how to apply multiple table in jpa.
kindly tell me please

thanks ,clear explanation.

may i know the annotations of the table?

i am trying to replicate this scenario on my project. it doesnt seem to work.

please help.

Hi Jair,

Great article! I see you are a big fan of hibernate criteria. I am in a bit of a predicament where I am joining two entities where one id is ‘integer’ (a) and one is ‘numeric’ (b). This is connexting to a db2 database. They join fine but when I run my queries they do not touch the db indexes. I am looking for a way to join the two entities and cast the numeric id to an integer as part of the join criteria. Do you know how to do this? The sql I want for the join is:

a.key=cast(b.key as integer)

This change makes a big difference to performance. An obvious solution is to change the datatypes in the db but unfortunately this is out of my control.

Any comments/suggestions welcome!

Cheers,
S

Hi, I have problem to apply this.
I don’t have method addAlias.
Neither I have field LEFT_JOIN on CriteriaSpecification.

sintaxe or syntax

How can i add another filter on the right table?
eg. left join children as child on p.id = child.id and child.gender=male.

Hi Jair,

i’ve found createCriteria(path,alias,joinType,withClause)… but this limits me to only one criteria after the join tablename on.. What if i need to have more than one criteria in the join column?

eg.

left join children as child on p.id = child.id and child.gender=male and childage > 5 and ……

Thanks,
Pao

Thanks Jair,

I believe you must be knowing the usage of Embedded Class which we use to define composite primary keys in an Entity class. However, it seems Hibernate Criteria is not able to read joins if I”m using Embedded objects to refer to an Entity class. Consider the following example:-

I’ve a three tables A, B & AB, where AB holds relationship between A & B and hence has a composite primary key which comprises of the primary key of A & primary key of B. I represent the relationship in hibernate as below (i’m using annotations):-

Entity class A.java
——————–

//imports…..

@Entity
@Table(name=”A”)
public class A{

private long aId;
….//other properties

private List bList; //I’ve deliberately given the name bList since using this I can get data of B.

@Id
@Column(name=”A_ID”)
public long getAId(){
return aId;
}
public void setAId(long aId){
this.aId = aId;
}

@OneToMany(mappedBy=”pk.a”)
public List getBList(){
return bList;
}
public void setBList(List bList){
this.bList = bList;
}

}

Entity class B.java
——————–

//imports…..

@Entity
@Table(name=”B”)
public class B{

private long bId;
private String name;
….//other properties

private List aList; //I’ve deliberately given the name bList since using this I can get data of A.

@Id
@Column(name=”B_ID”)
public long getBId(){
return bId;
}
public void setId(long bId){
this.bId = bId;
}

@Column(name=”B_NM”)
public String getName(){
return name;
}
public void setName(String name){
this.name = name;
}

@OneToMany(mappedBy=”pk.b”)
public List getAList(){
return aList;
}
public void setAList(List aList){
this.aList = aList;
}

}

Entity class AB.java
——————–

//imports…..

@Entity
@Table(name=”AB”)
public class AB{

private AB_pk pk;
….//other properties

//Constructor to set PK object
public AB(A a, B b){
pk = new AB_pk();
pk.setA(a);
pk.setB(b);
}

@EmbeddedId
public AB_pk getPk(){
return pk;
}
public void setPk(AB_pk pk){
this.pk = pk;
}

}

Embeddable class AB_pk.java
—————————–

//imports…..

@Embeddable
public class AB{

private A a;
private B b;

public AB_pk(){ } //Empty constructor – required

@ManyToOne
@JoinColumn(name=”A_ID”)
public A getA(){
return a;
}
public void setA(A a){
this.a = a;
}

@ManyToOne
@JoinColumn(name=”B_ID”)
public B getB(){
return b;
}
public void setB(B b){
this.b = b;
}

}

Criteria code block
——————–

Criteria criteria = session.createCriteria(A.class);
criteria.createCriteria(“bList”, “ab”, CriteriaSpecification.INNER_JOIN);
criteria.createAlias(“ab.pk”, “pk”);
criteria.createCriteria(“pk.B”, “b”, CriteriaSpecification.INNER_JOIN);
ProjectionList projections = Projections.projectionList();
projections.add(Projections.property(“b.name”), “bName”);
criteria.setProjection(projections);
criteria.add(Restrictions.eq(“aId”, Long.valueOf(2733)));
List list = criteria.list();

SQL Query formed by Hibernate
——————————

SELECT b.B_NM FROM A a INNER JOIN AB ab WHERE a.A_ID = 2733

If you notice that it’s able to identify B_NM column through the Embedded ID relationship in Projections but the inner join specified in Criteria wasn’t added by hibernate in the SQL query generated by itself.

Do you know where the problem is? Am I missing something here?

Hi Jair,
Thanks for nice example. I have 3 tables and corresponding entities. I need to join 3 tables using criteria. I hope you can solve this problem.

Thanks,
Raghu