Despite the use of lazy fetch, Hibernate JPA OnToone is still inquiring

Query query = entityManager.createQuery( "SELECT c FROM top_players c WHERE c.teamId=:teamId ORDER BY c.level DESC, c.adjustedFantasyPointsTotal DESC, c.id ASC" );
 query.setParameter( "teamId", teamId );
 List results = query.getResultList();
< br />

 @XmlAccessorType( XmlAccessType.PROPERTY)
@Entity( name="player_template")
@Table( name="player_template" )
@Cache (usage = CacheConcurrencyStrategy.READ_WRITE)
public class QhPlayer implements Serializable {

 @Id
 public Integer getPlayerTemplateId() {
 return playerTemplateId;
 }< br />
 @OneToOne( mappedBy ="playerTemplate", fetch = FetchType.LAZY)
 @XmlTransient
 public PlayerInventoryItem getInventoryItem() {
 return inventoryItem;
} 

}


@Entity( name = "qhplayer_inventory_item" )
@DiscriminatorValue("PLAYER")
@Ca che(usage = CacheConcurrencyStrategy.READ_WRITE)
public class PlayerInventoryItem extends InventoryItem {
 private QhPlayer playerTemplate;

 @OneToOne(fetch = FetchType.LAZY)
 @JoinColumn( name="player_template_id")
 @XmlTransient
 public QhPlayer getPlayerTemplate() {
 return playerTemplate;
 }
}



@Entity( name="inventory_item" )
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(
 name = "inventory_item_type",
 discriminatorType = DiscriminatorType.STRING
)
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public abstract class InventoryItem {
 private int inventoryItemId;
}



@Entity( name = "top_players")
@XmlRootElement(name = "top_player")
@Table(name="player")
@SecondaryTables ({
 @SecondaryTable(name="player_stats", pkJoinColumns={
 @PrimaryKeyJoinColumn(name="playerId", referencedColumnName="id")
 }),
 @SecondaryTable(name="player_mapping", pkJoinColumns={
 @PrimaryKeyJoinColumn(name="playerId" , referencedColumnName="id")
 }) 
})
@XmlAccessorType( XmlAccessType.PROPERTY )
public class TopPlayers {

 private QhPlayer playerTemplate; 

 @XmlTransient
 @ManyToOne
 @JoinColumn( table="player_mapping", name = "player_template_id", nullable = true )
 public QhPlayer getPlayerTemplate() {< br /> return playerTemplate;
 }
}

The problem I have encountered is that Hibernate queries for a class on the other side of the lazy onetoone relationship.

The query for top_players (depending on Cache settings) through mapping Query the table to obtain the ID of the QHPlayer table.

After executing the main query, it queries each instance of the QHPlayer table.

However, it is in two different scenarios I did it wrong.

If I turn on the cache, it will query the instance of QHPlayer, and then it will query to the inventory_item table.
If I turn off the cache, it will query QHPlayer by adding inventory_item .

The problem is that no matter what I do, it insists on querying the inventory_item table. This is what I don’t want. I don’t need data
currently in inventory_item.

I assume QHPlayer and PlayerInventoryItem There is a problem with the onetoone statement.

Any thoughts?

The relevant code is as follows:

Query query = entityManager.createQuery( "SELECT c FROM top_players c WHERE c.teamId=:teamId ORDER BY c.level DESC, c.adjustedFantasyPointsTotal DESC, c.id ASC" );
 query.setParameter( "teamId", teamId );
 List results = query.getResultList();
< br />

 @XmlAccessorType( XmlAccessType.PROPERTY)
@Entity( name="player_template")
@Table( name="player_template" )
@Cache (usage = CacheConcurrencyStrategy.READ_WRITE)
public class QhPlayer implements Serializable {

 @Id
 public Integer getPlayerTemplateId() {
 return playerTemplateId;
 }< br />
 @OneToOne( mappedBy ="playerTemplate", fetch = FetchType.LAZY)
 @XmlTransient
 public PlayerInventoryItem getInventoryItem() {
 return inventoryItem;
} 

}


@Entity( name = "qhplayer_inventory_item" )
@DiscriminatorValue("PLAYER")
@Cache (usage = CacheConcurrencyStrategy.READ_WRITE)
public class PlayerInventoryItem extends InventoryItem {
 private QhPlayer playerTemplate;

 @OneToOne(fetch = FetchType.LAZY)
 @JoinColumn(name ="player_template_id")
 @XmlTransient
 public QhPlayer getPlayerTemplate() {
 return playerTemplate;
 }
}


 
@Entity( name="inventory_item" )
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(
 name = "inventory_item_type",
 discriminatorType = DiscriminatorType .STRING
)
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public abstract class InventoryItem {
 private int inventoryItemId;
}

 

@Entity( name = "top_players")
@XmlRootElement(name = "top_player")
@Table(name="player")
@SecondaryTables( {
 @SecondaryTable(name="player_stats", pkJoinColumns={
 @PrimaryKeyJoinColumn(name="playerId", referencedColumnName="id")
 }),
 @SecondaryTable(name="player_mapping", pkJoinColumns={
 @PrimaryKeyJoinColumn(name="playerId" , referencedColumnName="id")
 }) 
})
@XmlAccessorType( XmlAccessType.PROPERTY )
public class TopPlayers {

 private QhPlayer playerTemplate; 

 @XmlTransient
 @ManyToOne
 @JoinColumn( table="player_mapping", name = "player_template_id", nullable = true )
 public QhPlayer getPlayerTemplate() {< br /> return playerTemplate;
 }
}

I found the answer.

This It’s because one to one can be empty. Then it can’t implement lazy loading of objects. So I solve it through a many-to-one relationship, just looking for a collection of objects.

This is a good reference .
http://community.jboss.org/wiki/Someexplanationsonlazyloadingone-to-one

Also thank anyone who reads this content.