两个表之间的java JPQL连接
我试图连接两个表,但无法找到合适的JPQL查询
这是我拥有的两个表的一个简单版本,在两个id_persona列之间有一个FK
TABLE macchine
marca (String) -- targa (String) -- id_persona (int)
TABLE persone
nome (String) -- id_persona (int)
我想在id_persona上加入他们,但我猜不出sintax和google的查询没有任何帮助
例如,我如何才能让每个“targa”由一个“id_persona”链接到一个给定的“nome”
人物角色
@Entity
public class Persone implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id_persona")
private int idPersona;
private String cognome;
private Timestamp data_nascita;
private String nome;
@OneToMany(mappedBy="persona")
@JoinColumn(name="id_persona")
private Set<Macchine> macchina;
}
-
Macchine
@Entity
public class Macchine implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id_persona")
private int idPersona;
private String targa;
private String marca;
@ManyToOne(fetch=FetchType.LAZY)
private Persone persona;
}
--
询问
public static List<Macchine> selectPM(){
Query selectAll = em.createQuery("SELECT m FROM Macchine m");
@SuppressWarnings("unchecked")
List<Macchine> jObj = selectAll.getResultList();
return jObj; //Join Objective
}
我编辑了答案,因为我在项目中做了一些更改。我有新的表格,我链接了
这就是我现在遇到的错误:
Error compiling the query [SELECT m.id_persona, m.targa, m.marca FROM Macchine m], line 1, column 9: unknown state or association field [id_persona] of class [model.Macchine]
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