删除继承类 JPA

Question

I have a table defined as this:

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
@DiscriminatorColumn(name = "EVENT_TYPE")
public abstract class Event implements Serializable {
    @Id
    @GeneratedValue
    private Long id;
...
}

Then I have this inherited tables:

@Entity
@DiscriminatorValue("BOOLEANVALUE")
public class BooleanValueEvent extends Event {
    ...
}

@Entity
@DiscriminatorValue("EXACTVALUE")
public class ExactValueEvent extends Event {
    ...
}

Hibernate creates two table in database, but when I try to delete on JPA an inherited object it returns foreign key constraint violation error, because It try to delete first Event class. How can I delete inherited class first when I delete superClass in order to avoid key constraint violation error?

Thank you.

Answer 1

Using cascade delete , removing a SubTable entity will succeed and it will remove both the subTable and the parentTable rows.

@Entity
@DiscriminatorValue("BOOLEANVALUE")
@OnDelete(action = OnDeleteAction.CASCADE)
public class BooleanValueEvent extends Event {
    ...
}

@Entity
@DiscriminatorValue("EXACTVALUE")
@OnDelete(action = OnDeleteAction.CASCADE)
public class ExactValueEvent extends Event {
    ...
}

Answer 2

Finally I solved it with.

@JsonTypeInfo(
        use = JsonTypeInfo.Id.NAME,
        include = JsonTypeInfo.As.PROPERTY,
        property = "typeName")
@JsonSubTypes({
        @Type(value = BooleanValueEvent.class),
        @Type(value = ExactValueEvent.class)
})
@Entity
@Inheritance(strategy=InheritanceType.JOINED)
@DiscriminatorColumn(name = "EVENT_TYPE")
public abstract class Event implements Cloneable, Serializable {
    @Id
    @GeneratedValue
    private Long id;
...
}

And

@Entity
@DiscriminatorValue("BOOLEANVALUE")
public class BooleanValueEvent extends Event {
    ...
}

@Entity
@DiscriminatorValue("EXACTVALUE")
public class ExactValueEvent extends Event {
    ...
}