Question

我面临以下问题。想象一下这个数据模型：

enter image description here

正如您所见， project_function 实体与多个实体关联。

这是我的实体类。

PeronalCard ：

@Entity
@Table(name = "personal_card")
@XmlRootElement
public class PersonalCard implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id_person")
    private Integer idPerson;

    /* SOME OTHER ATTRIBUTES */

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "projectFunctionPK.personalCard")
    private Set<ProjectFunction> projectFunctionSet;

    public PersonalCard() {
    }

    public Integer getIdPerson() {
        return idPerson;
    }

    public void setIdPerson(Integer idPerson) {
        this.idPerson = idPerson;
    }

    @XmlTransient
    public Set<ProjectFunction> getProjectFunctionSet() {
        return projectFunctionSet;
    }

    public void setProjectFunctionSet(Set<ProjectFunction> projectFunctionSet) {
        this.projectFunctionSet = projectFunctionSet;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (idPerson != null ? idPerson.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof PersonalCard)) {
            return false;
        }
        PersonalCard other = (PersonalCard) object;
        if ((this.idPerson == null && other.idPerson != null) || (this.idPerson != null && !this.idPerson.equals(other.idPerson))) {
            return false;
        }
        return true;
    }

}

项目：

@Entity
@Table(name = "project")
@XmlRootElement
public class Project implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id_project")
    private Integer idProject;

    /* OTHER ATTRIBUTES*/

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "projectFunctionPK.project")
    private Set<ProjectFunction> projectFunctionSet;

    public Project() {
    }

    public Integer getIdProject() {
        return idProject;
    }

    public void setIdProject(Integer idProject) {
        this.idProject = idProject;
    }

    @XmlTransient
    public Set<ProjectFunction> getProjectFunctionSet() {
        return projectFunctionSet;
    }

    public void setProjectFunctionSet(Set<ProjectFunction> projectFunctionSet) {
        this.projectFunctionSet = projectFunctionSet;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (idProject != null ? idProject.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Project)) {
            return false;
        }
        Project other = (Project) object;
        if ((this.idProject == null && other.idProject != null) || (this.idProject != null && !this.idProject.equals(other.idProject))) {
            return false;
        }
        return true;
    }

}

ProjectFunction ：

@Entity
@Table(name = "project_function")
@XmlRootElement
@AssociationOverrides({
    @AssociationOverride(name = "projectFunctionPK.project", 
        joinColumns = @JoinColumn(name = "id_project", referencedColumnName = "id_project")),
    @AssociationOverride(name = "projectFunctionPK.personalCard", 
        joinColumns = @JoinColumn(name = "id_person", referencedColumnName = "id_person")) })
public class ProjectFunction implements Serializable {
    private static final long serialVersionUID = 1L;

    protected ProjectFunctionPK projectFunctionPK;

    private Date fromd;    
    private Date tod;

    public ProjectFunction() {
        this.projectFunctionPK = new ProjectFunctionPK();
    }

    @EmbeddedId
    public ProjectFunctionPK getProjectFunctionPK() {
        return projectFunctionPK;
    }

    public void setProjectFunctionPK(ProjectFunctionPK projectFunctionPK) {
        this.projectFunctionPK = projectFunctionPK;
    }

    @Column(name = "fromd")
    @Temporal(TemporalType.DATE)
    public Date getFromd() {
        return fromd;
    }

    public void setFromd(Date fromd) {
        this.fromd = fromd;
    }

    @Column(name = "tod")
    @Temporal(TemporalType.DATE)
    public Date getTod() {
        return tod;
    }

    public void setTod(Date tod) {
        this.tod = tod;
    }

    @Transient
    public Project getProject() {
        return projectFunctionPK.getProject();
    }


    public void setProject(Project project) {
        this.projectFunctionPK.setProject(project);
    }

    @Transient
    public PersonalCard getPersonalCard() {
        return this.projectFunctionPK.getPersonalCard();
    }

    public void setPersonalCard(PersonalCard personalCard) {
        //this.personalCard = personalCard;
        this.projectFunctionPK.setPersonalCard(personalCard);
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (projectFunctionPK != null ? projectFunctionPK.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof ProjectFunction)) {
            return false;
        }
        ProjectFunction other = (ProjectFunction) object;
        if ((this.projectFunctionPK == null && other.projectFunctionPK != null) || (this.projectFunctionPK != null && !this.projectFunctionPK.equals(other.projectFunctionPK))) {
            return false;
        }
        return true;
    }

}

最后我的嵌入式主键 ProjectFunctionPK ：

@Embeddable
public class ProjectFunctionPK implements Serializable {

    @ManyToOne
    private Project project;
    @ManyToOne
    private PersonalCard personalCard;

    public ProjectFunctionPK() {
    }

    public Project getProject() {
        return project;
    }

    public void setProject(Project project) {
        this.project = project;
    }

    public PersonalCard getPersonalCard() {
        return personalCard;
    }

    public void setPersonalCard(PersonalCard personalCard) {
        this.personalCard = personalCard;
    }

    @Override
    public int hashCode() {
        int hash = 3;
        hash = 41 * hash + Objects.hashCode(this.project);
        hash = 41 * hash + Objects.hashCode(this.personalCard);
        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final ProjectFunctionPK other = (ProjectFunctionPK) obj;
        if (!Objects.equals(this.project, other.project)) {
            return false;
        }
        if (!Objects.equals(this.personalCard, other.personalCard)) {
            return false;
        }
        return true;
    }

}

首先我保存项目。它工作正常。然后我想使用project_function连接它 - 所以我创建project_function设置它们现有的项目和personal_card，并在尝试保持后我得到以下错误：

Caused by: org.postgresql.util.PSQLException: ERROR: column projectfun0_.personalcard does not exist
  Position: 8
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:561)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:419)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:304)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:82)
    ... 119 more

显然Hibernate不知道projectfun0_.personalcard。但我不知道为什么。您是否在实体类中看到任何错误？或者错误可能在其他地方？

非常感谢您的所有答案：）

Answer 1

EmbeddedId documentation

不支持嵌入式id类中定义的关系映射。

因此，ProjectFunctionPK应仅包含基本映射，实体映射应在实体本身中完成。以下是一些相关的帖子

https://stackoverflow.com/a/9760808/4074715
https://stackoverflow.com/a/4692144/4074715

列不存在 - Hibernate ManyToMany关联类

1 个答案: