NOT INCLUDING a test case right now as I like to hear about your opinion on this first . And, considering that your are familiar with the code, that should be rather easy to do, or isn't it?
Having a class hierarchy like so
{code:title=AbstractEntity.java|borderStyle=solid}
import java.io.Serializable;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.MappedSuperclass;
@MappedSuperclass
public abstract class AbstractEntity
implements Serializable
{
@ManyToOne(optional = false)
@JoinColumn(name = "ref_id", referencedColumnName = "id", nullable = false)
private ReferencedEntity realm;
protected AbstractEntity()
{
}
public ReferencedEntity getRef()
{
return ref;
}
public void setRef(final ReferencedEntity ref)
{
this.ref = ref;
}
}
{code}
{code:title=ReferencedEntity.java|borderStyle=solid}
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public abstract class ReferencedEntity
implements Serializable
{
@Id
private int id;
public ReferencedEntity()
{
super();
}
public int getId() { return id; }
public int setId(int id) { this.id = id; }
}
{code}
{code:title=ConcreteEntity.java|borderStyle=solid}
import java.io.Serializable;
import javax.persistence.AssociationOverride;
import javax.persistence.AssociationOverrides;
import javax.persistence.Entity;
import javax.persistence.ForeignKey;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
@Entity
@AssociationOverrides({
@AssociationOverride(name = "ref",
joinColumns = @JoinColumn(name = "ref_id"),
foreignKey = @ForeignKey(name = "FK_CONCRETEENT_REF"))
})
public abstract class ConcreteEntity
implements Serializable
{
@Id
private int id;
public ConcreteEntity()
{
super();
}
public int getId() { return id; }
public int setId(int id) { this.id = id; }
}
{code}
{code:title=persistence.xml|borderStyle=solid}
<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0">
<persistence-unit name="modelBase" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<!- ... ->
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/coyapp?useUnicode=true&useJDBCCompliantTimezoneS‌​hift=true&useLegacyDatetimeCode=false&serverTimezone=UTC" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="root" />
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.hbm2ddl.auto" value="create-drop" />
<!--<property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:mem:testdb"/>
<property name="javax.persistence.jdbc.user" value="sa"/>
<property name="javax.persistence.jdbc.password" value=""/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>-->
</properties>
</persistence-unit>
</persistence>
{code}
The overridden foreign key for the AbstractEntity#ref property is never applied and hibernate will use the default foreign key for all derived entity classes.
Having debugged a little bit, it seems that overriding foreign key names is not yet supported as overriding for example nullable does work.
Since I have a rather large number of entities for my next project that all derive from the same mapped superclass, not having this feature is quite a bummer as I now must refactor all such associations into the concrete entity classes. And these are quite a lot. As a last resort, I can always also hand craft the schema, but this means additional workflow overhead... |
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