我们对PostgreSQL中的继承以及在JPA中将其映射为实体存在疑问。我们的数据库和我们要映射的表是：

CREATE TABLE Answer (
    idAnswer SERIAL,
    answerContent VARCHAR,
    idQuestion INTEGER,
    version INTEGER,

    CONSTRAINT Answer_idAnswer_PK PRIMARY KEY (idAnswer),
    CONSTRAINT Answer_idQuestion_FK FOREIGN KEY (idQuestion) REFERENCES Question(idQuestion)
);


CREATE TABLE MatchAnswer (
    matchingAnswer VARCHAR NOT NULL,
    version INTEGER,

    CONSTRAINT MatchAnswer_idAnswer_PK PRIMARY KEY (idAnswer)       
) INHERITS(Answer);


CREATE TABLE TrueFalseAnswer (
    isTrue BOOLEAN NOT NULL,
    version INTEGER,

    CONSTRAINT TrueFalseAnswer_idAnswer_PK PRIMARY KEY (idAnswer)   
) INHERITS(Answer);

我们在Netbeans 7.1.2中使用自动工具将它们映射到实体。起初我认为仅添加就足够了

@Entity
@Table(name = "truefalseanswer", catalog = "jobfairdb", schema = "public")
@XmlRootElement
public class Truefalseanswer extends Answer implements Serializable {
    private static final

因此，它只是 扩大了 ，但无法正常工作。最好的方法是什么？提前致谢。