JPA query many to one association - jpa

Question

I want to build the following pseudo query
Select a From APDU a where a.group.id= :id
group is a field in APDU class of the type APDUGroup.class.
I just want to get a list of APDUs based on APDUGroup's id.
How do i do that using a standard JPA query?
UPDATE
Yes, I have tried the above query and tried other variations for hours before posting in S/O. Here is the generated SQL for the query above:
SELECT t1.ID, t1.status, t1.type, t1.modified, t1.response, t1.expectedSize, t1.created, t1.description, t1.sequence, t1.name, t1.command, t1.recurring, t1.auth, t1.createdBy, t1.APDUGroup, t1.modifiedBy FROM APDUGroup t0, APDU t1 WHERE ((t0.ID = ?) AND (t0.ID = t1.APDUGroup))
The query looks okay but nothing get selected from my table.
There are at least 100 APDUs with APDUGroup = 1 in my test database.
I'm using eclipselink as the JPA provider.

Answer 1

Given the following Entities:
#Entity
public class APDU implements Serializable {
#Id
#GeneratedValue
private Long id;
#ManyToOne
private APDUGroup group;
//...
}
#Entity
public class APDUGroup implements Serializable {
#Id
#GeneratedValue
private Long id;
//...
}
The following query will return a list of APDUs for a given APDUGroup id:
select a from APDU a where a.group.id = :id
Oh, wait, that's your query :)

Answer 2

Entity 1:
#Entity
#Getter
#Setter
#Table(name = "invoices")
public class Invoice implements Serializable {
#Id
#GeneratedValue
#Column(name = "invoice_id", updatable = false, nullable = false)
private Long invoiceId;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "person_id", referencedColumnName = "person_id", insertable = false, updatable = false, nullable = false)
private Person person;
//...
}
Entity 2:
#Entity
#Getter
#Setter
#Table(name = "people")
public class Person implements Serializable {
#Id
#GeneratedValue
#Column(name = "person_id", updatable = false, nullable = false)
private Long personId;
//...
}
Finally, Your Data Access Object (JPA Repository)
#Repository
public interface InvoiceRepository extends JpaRepository<Invoice, Long> {
#Query(value="SELECT x FROM Invoice x WHERE x.person.personId = :myPersonId")
List<Invoice> findInvoiceByPersonId (long myPersonId);
}
I hope this example has been helpful :)