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OneToMany, org.hibernate.QueryException: could not resolve property

I my project I have to class
#Entity
#Table(name = "asset")
public class Asset extends BaseEntity {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "last_position")
private Position lastPosition;
/**contructor, getter, setter method, other field etc..**/
}
and another class
#Entity
#Table(name = "position")
#EntityListeners(EntityChangeCallback.class)
public class Position extends BaseEntity {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#OneToMany(mappedBy="lastPosition")
private List<Asset> assets;
/**contructor, getter, setter method, other field etc..**/
}
Data Access Object like this
public abstract class BaseDaoImp<E extends Indexable> implements BaseDao<E> {
#PersistenceContext
protected EntityManager em;
/**some thing else**/
#SuppressWarnings("unchecked")
public List<E> list() {
Query qry = em.createQuery("from " + getType().getSimpleName() + " u");
return qry.getResultList();
}
}
when i run the code. I get the error
Caused by: java.lang.IllegalArgumentException:
org.hibernate.QueryException: could not resolve property:
lastPositionId of: com.abc.server.db.entity.Asset [FROM
com.abc.server.db.entity.Position pos WHERE pos.deviceId IN
('100 000000001000','100000000001001','100000000001002') AND pos.id IN
(SELECT asset.lastPositionId FROM com.tma.ats.am.server
.db.entity.Asset asset)]
I found the problem is Hibernate generate query with field name lastPositionId Instead of lastPosition. I change field name from lastPosition to lastPositionId. Everything work Ok. But I read many example on web and from my own project. All other field can map #ManyToOne Ok and they don't need Postfix Id. How can i make above code work with field name lastPosition (not lastPositionId) ?
Thank for any help.

there is a property in your jpa xml configuration file called hibernate.hbm2ddl.auto. Change its value to create or create-drop to apply new changes.

Javax validation error when save a class which include ManyToOne relationship

I want to save Tesis class using entityManager.persist() method but I get following error.
Caused by: javax.validation.UnexpectedTypeException: HV000030: No validator could be found for type: thymeleafexamples.layouts.acenta.Acenta.
#Entity
public class Tesis {
public Tesis(){
}
public Tesis(String adi, Acenta acenta) {
this.adi = adi;
this.acenta = acenta;
}
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#NotEmpty
private String adi;
#NotEmpty
#ManyToOne(fetch = FetchType.EAGER,cascade=CascadeType.ALL)
#JoinColumn(name="acenta_id")
private Acenta acenta;
//GETTERS AND SETTERS
}
/////////////////////////////////////////////////////////////////////
#SuppressWarnings("serial")
#Entity
public class Acenta implements java.io.Serializable {
public Acenta(String adi) {
this.adi = adi;
}
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#NotEmpty
private String adi;
#OneToMany(mappedBy="acenta")
private Set<Tesis> tesiss;
}

According to Hibernate Validator's API org.hibernate.validator.constraints.NotEmpty annotation
"asserts that the annotated string, collection, map or array is not
null or empty"
Based on the above definition Acenta type is not a valid type to check. You may consider using javax.validation.constraints.NotNull annotation instead as it's valid for all types and moreover not vendor specific.

How to get the ID (PRIMARY KEY) from an entity object after commit transaction?

After I persist an object and commit like this:
Version version = new Version();
version.setVersion(getNext(this.version));
version.setProjectID(projectID);
em.persist(version);
em.getTransaction().commit();
I want to get the ID(Primary Key) by this code line:
Object id = factory.getPersistenceUnitUtil().getIdentifier(version);
I can get the Version and ProjectID but the ID is null. The ID is auto generated but still return null. I tried to implement #GeneratedValue(strategy=GenerationType.IDENTITY) in my entity class but nothing change. Any solution for me?
EDIT WITH MORE CODE
Version Entity: this is using an EmbededId
#Entity
#NamedQuery(name="Version.findAll", query="SELECT v FROM Version v")
#Table(name="Version")
public class Version implements Serializable {
#EmbeddedId
#GeneratedValue(strategy=GenerationType.SEQUENCE)
private VersionPK id;
#Column(name="Version")
private String version;
#Column(name="ProjectID")
private int projectID;
Embeddable class:
#Embeddable
public class VersionPK implements Serializable {
//default serial version id, required for serializable classes.
private static final long serialVersionUID = 1L;
#Column(name="ID")
private int id;
public VersionPK() {
}

You have to use flush() after commiting to be able to get the id:
em.persist(version);
em.getTransaction().commit();
em.flush();
Then just use getter to have the id:
Object id = version.getId();//getId() is the getter of the id in your entity.
See the answer here.

version column does not get increased with JPA (Hibernate)

I have the following Entity structure:
public abstract class BaseEntity {
private int _version;
public BaseEntity() {
}
#Version
#Column(name = "oplock", nullable = false)
private int getVersion() {
return _version;
}
#SuppressWarnings("unused")
private void setVersion(final int version) {
_version = version;
}
//some other code goes here....
}
the concrete Entity:
#Table(name="my_table", schema="public",
uniqueConstraints=#UniqueConstraint(columnNames={"username", "attribute"})
)
public class MyEntity extends BaseEntity implements java.io.Serializable {
private int id;
private String username;
private String attribute;
private String op;
private String value;
public MyEntity() {
}
//some code goes here ....
}
Now, I select from the database an entity of MyEntity type, lock it with entityManager.lock(myEntityInstance, LockModeType.OPTIMISTIC);, modify it, and persist modifications. The thing that I expect to get is to have oplock column's value incremented (oplock is the version column), but it is untouched.
Question: Does it behave right or am I missing something? I think the right behavior would be that the oplock's value would be incremented.
Edit: After I switched from hibernate 3.6 to hibernate 4.1, I still get the same behavior.

Finally I solved my problem:
I put only #MappedSuperclass annotation above BaseEntity class. For more details you can read here.

JPA Mapping Error -not provided sufficient metadata in your id class

I am trying to do mapping in JPA.
#Entity
public class Auction {
#Id
private Integer auctionId;
#OneToMany(mappedBy="auctionId")
#MapKey(name="auctionParamId")
private Map<AuctionParam, AuctionParamValue> values;
}
#Entity
public class AuctionParam {
#Id
private Integer auctionParamId;
private String description;
}
#Entity
public class AuctionParamValue {
#EmbeddedId
private AuctionParamValuePK pk;
private String value;
}
#Embeddable
public class AuctionParamValuePK {
#ManyToOne
#JoinColumn(name="auctionId")
private Auction auction;
#ManyToOne
#JoinColumn(name="auctionParamId")
private AuctionParam auctionParam;
}
Showing an error:-
.Error-Details:-Exception Description:
Entity [class
com.eaportal.domain.AuctionParamValue]
uses [class
com.eaportal.domain.AuctionParamValuePK]
as embedded id class
whose access-type
has been determined as [FIELD].
But
[class
com.eaportal.domain.AuctionParamValuePK]
does not define any [FIELD]. It is
likely that you have not provided
sufficient metadata in your id class
[class
com.eaportal.domain.AuctionParamValuePK].
If you come up with a solution please let me know.
Thanks in Advance
Tushar

You cannot use an EmbeddedId with relationships. Use an IdClass.
#Entity
#IdClass(AuctionParamValuePK.class)
public class AuctionParamValue {
#Id
#ManyToOne
#JoinColumn(name="auctionId")
private Auction auction;
#Id
#ManyToOne
#JoinColumn(name="auctionParamId")
private AuctionParam auctionParam;
#Basic
private String value;
}
public class AuctionParamValuePK {
private int auction;
private int auctionParam;
}

I think there are some errors in your Auction class. This is how I think it should look
#Entity
public class Auction {
#Id
private Integer auctionId;
#OneToMany(mappedBy="auction") // not auctionId
#MapKey(name="auctionParam") // not auctionParamId
private Map<AuctionParam, AuctionParamValue> values;
}
(The annotation values have to correspond with fields (or properties), not with columns)