CODEWITHSUNDEEP
hibernatehibernate-mapping
user2440712
user2440712

Reputation: 719

Query many to many relationship with DetachedCriteria

Right now I have 3 tables in database:

Table A:
id:
...

Table B:
id:
...

Table C:
A_id:
B_id:
...

The mapped object is like this:

@Entity
@Table(name="A")
Class A{
    Long id;

    @ManyToMany
    @Fetch(FetchMode.SELECT)
    @JoinTable(name="C",joinColumns={@JoinColumn(name="A_id")},inverseJoinColumns={@JoinColumn(name="B_id")})
    List<B> Bs;
}

@Entity
@Table(name="B")
Class B{
    Long id;
}

Now I would like to use DetachedCriteria to do a query to find all A entities with A.Bs contains a specific B. Is it possible to do the query with DetachedCriteria.

I think the sql should be 

Select A.* 
From A inner join C on A.id=C.A_id inner join B on B.id=C.B_id 
Where B.id=?

Thanks a lot! Any help will be greatly appreciated.

Upvotes: 1

Views: 1631

Answers (1)

JB Nizet
JB Nizet

Reputation: 691745

In HQL, it would simply be

select a from A a inner join a.bs b where b.id = :id

And it translates directly to criteria:

Criteria c = session.createCriteria(A.class, "a");
c.createAlias("a.bs", "b");
c.add(Restrictions.eq("b.id", bId);

As always, the link to the documentation explaining it.

Upvotes: 4

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