Question

这里的工作有一组员工，而员工有一组工作，但Spring给我这个例外

引起：org.hibernate.MappingException：外键（FK1kec5bwba2rl0j8garlarwe3d：account [employee_id]））必须有相同的列数作为引用的主键（员工 [JOB_ID，EMPLOYEE_ID]）

这是我的员工班：

@Entity
public class Employee {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id ;
private String firstname ;
private String lastname ;
private String email ;
private String phone ;
private String address ;
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "account_id")
private Account account ;

public Account getAccount() {
    return account;
}
public void setAccount(Account account) {
    this.account = account;
}

@ManyToOne
@JoinColumn(name = "departement_id")
@JsonIgnore
private Departement departement ;
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "jobs", joinColumns = @JoinColumn(name = "employee_id", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "job_id", referencedColumnName = "id"))
private Set<Job>jobs ;


....

}

这是我的工作班：

@Entity
@Inheritance

public abstract class Job {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id ;

private String status ; // (pending or done)
private Date date ;

@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "employee", joinColumns = @JoinColumn(name = "job_id", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "employee_id", referencedColumnName = "id"))
private Set<Employee> employee ;

@ManyToOne
@JoinColumn(name = "BusinnesPartner_id")
@JsonIgnore
private BusineesPartner busineesPartner ;








}

请你解释一下为什么我会得到这个例外。

Answer 1

@JoinTable注释应该在拥有实体端使用，在另一方面你不应该有@JoinTable，你需要有mappedBy来定义反向关系，因为你建立双向关系是如果Job是拥有您需要修改Employee pojo的实体

@ManyToMany(cascade = CascadeType.ALL, mappedBy="employee")
private Set<Job>jobs ;

外键必须具有与manyToMany引用的主键相同的列数

1 个答案: