向社区致以问候，
我整天都在努力寻找以下问题的解决方案。
场景如下，我有一个表
---TABLE_ONE---
INT ID
VARCHAR NAME
PRIMARY_KEY (ID)
我的另一个表由三列组成，它们由一个组合键组成
---TABLE_TWO---
INT TABLE_ONE_ID (FK -> TABLE_ONE.ID)
VARCHAR NAME
VARCHAR EMAIL
PRIMARY_KEY(TABLE_ONE_ID, NAME, EMAIL)
我想要实现的关系是TABLE_ONE实体将 具有TABLE_TWO中的对象列表(一对多关系(。
我尝试这样做，如下所示。
@Entity
@Table(name = "TABLE_ONE")
public class TableOne {
@Column(name="id")
private int id;
@Column(name="name")
private String name
@OneToMany(fetch = FetchType.EAGER, mappedBy = "tableOne")
private List<TableTwo> tableTwoList;
//getters, setters, constructors
}
@Entity
@Table(name = "TABLE_TWO")
public class TableTwo {
@EmbeddedId
private TableTwoCompositeId tableTwoCompositeId;
@ManyToOne
@JoinColumn(name = "TABLE_ONE_ID", referencedColumnName = "ID", insertable = false, updatable = false)
private TableOne tableOne;
//getters, setters, constructors
}
@Embeddable
public class TableTwoCompositeId {
@Column(name = "TABLE_ONE_ID")
public Integer provider;
@Column(name = "NAME")
public String name;
@Column(name = "EMAIL")
public String email;
//getters, setters, constructors
}
但是，当从数据库中检索 TableOne 对象时，我javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not extract ResultSet和Caused by: java.sql.SQLSyntaxErrorException: ORA-00942: table or view does not exist。
提前感谢任何帮助！
我认为您需要进行一些小的更改：
-
TableOne.id需要@Id注释 TableTwoCompositeId.provider的类型应与TableOne.id的类型匹配-
TableTwo.tableOne需要一个@MapsId注释来指示它映射TableTwoCompositeId.provider
代码应如下所示：
@Entity
@Table(name = "TABLE_ONE")
public class TableOne {
@Id
@Column(name="id")
private int id;
@Column(name="name")
private String name
@OneToMany(fetch = FetchType.EAGER, mappedBy = "tableOne")
private List<TableTwo> tableTwoList;
//getters, setters, constructors
}
@Entity
@Table(name = "TABLE_TWO")
public class TableTwo {
@EmbeddedId
private TableTwoCompositeId tableTwoCompositeId;
@MapsId("provider") // maps provider attribute of embedded id
@ManyToOne
@JoinColumn(name = "TABLE_ONE_ID", referencedColumnName = "ID", insertable = false, updatable = false)
private TableOne tableOne;
//getters, setters, constructors
}
@Embeddable
public class TableTwoCompositeId {
@Column(name = "TABLE_ONE_ID")
public int provider;
@Column(name = "NAME")
public String name;
@Column(name = "EMAIL")
public String email;
//getters, setters, constructors
}