Hi,
Here is a simple example:
(1) EntityA.java:
package queryTest;
import javax.persistence.*;
@SqlResultSetMapping(name="ResultCMapping",
entitie...@entityresult(entityClass=ResultC.class)}
)
@NamedNativeQuery(
name="nativefindAandB",
query="SELECT a.id, a.name, b.value FROM EntityA a, EntityB b WHERE a.id =
b.id",
resultSetMapping="ResultCMapping"
)
@Entity
public class EntityA {
@Id
private long id;
@OneToOne
private EntityB b;
String name;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public EntityB getB() {
return b;
}
public void setB(EntityB b) {
this.b = b;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
=================================
(2) EntityB.java:
package queryTest;
import javax.persistence.*;
@Entity
public class EntityB {
@Id
long id;
String value;
@OneToOne
EntityA a;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public EntityA getA() {
return a;
}
public void setA(EntityA a) {
this.a = a;
}
}
======================================
(3) query:
List<ResultC> list1 =
em.createNamedQuery("nativefindAandB").getResultList();
for (ResultC c: list1) {
System.err.println("value = " + c.getValue());
}
Hope this helps.
--- On Tue, 4/21/09, [email protected] <[email protected]>
wrote:
> From: [email protected] <[email protected]>
> Subject: NativeQuery resulting in combination of Values
> To: [email protected]
> Date: Tuesday, April 21, 2009, 1:22 AM
> Hello,
>
> I'm currently trying to build a native query for ORACLE
> that combines
> several columns of different tables in a complex JOIN/UNION
> way including
> some ORACLE specific things that do not allow me to
> redesign it for
> JPA-native querys. However, I'm having trouble to
> understand how to handle
> this kind of 'virtual' result set. I figured that I have to
> use an
> @SqlResultSetMapping() somewhere on the resulting object.
>
> My problems arise here, which lead to several questions:
>
> If I design a Result-Object, how do I tell JPA that this
> shall be the
> represence of a single row of the ResultSet? I can't use
> @Entity nor
> @Table somehow, cause I always get error messages telling
> me that there is
> no such table (which is correct)
> What is the correct way of using SqlResultSetMapping for a
> simple result
> with 12 columns that shall be mapped to 12 simple values in
> the resulting
> 'Entity'?
> Does anybody have a good (maybe commented) example of such
> a
> ResultSetMapping?
> Where exactly do you put the SqlResultSetMapping? Do you
> annotate the
> class that shall hold a row? Do I have to register that
> class in
> persistence.xml?
>
> My current solution always stucks with error messages
> like:
>
> Invalid Index (Oracle Error)
> the Message: Result path "{2}" in result type "{1}" of
> mapping "{0}"
> attempts to map a field that does not have exactly 1
> column. (I figured it
> actually can't find a single column)
> Table "{0}" given for "{1}" does not exist. (Happens when I
> try to use
> @Entity on the resulting type)
>
> Any help on these questions is gladly appreciated.
>
> Thanks,
>
> Heiko
>
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