Question

我的问题是我无法在我的选择查询中包含类的集合属性我确实在两个班级（团队和成员）之间有父/子关系

为了提高提取性能我想使用HSL查询来仅选择返回对象的必要属性（Row）这可以通过以下方式完成：

List<Object> returnlist = session.createQuery("select t.name, t.members from Team t").list();

但这会导致hibernate异常：

WARN org.hibernate.util.JDBCExceptionReporter,JDBCExceptionReporter:100 - SQL Error: -1, SQLState: 42X01
ERROR org.hibernate.util.JDBCExceptionReporter,JDBCExceptionReporter:101 - Syntax error: Encountered "." at line 1, column 33.

我在下面附上了完整的类源。非常感谢你提前帮助我 Du我必须放置一个额外的连接来使它工作，或者这是一个hibernate错误？

Team.java

@Entity()
@Table(name = "TEAM")
public class Team implements Serializable {

  private Long id; 
  private String name;
  private String remark; 
  private List<Member> members = new ArrayList<Member>();

  @Id
  @Column(name = "id")
  @GeneratedValue(strategy=GenerationType.AUTO)
  public Long getId() {
      return id;
  }

  public void setId(Long id) {
      this.id = id;
  }

  @CollectionOfElements
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy="team")
  public List<Member> getMembers() {
      return members;
  }


  public void addMember(Member member) {
      if (!getMembers().contains(member)) {
        getMembers().add(member);
          if (member.getTeam() != null) {
            member.getTeam().getMembers().remove(members);
          }
          member.setTeam(this);
      }
  }

  public void setMembers(List<Member> members) {
      this.members = members;
  }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setRemark(String remark) {
        this.remark = remark;
    }

    public String getRemark() {
        return remark;
    }

}

Member.java

@Entity()
@Table(name = "MEMBER")
public class Member implements Serializable {

    private Long id;
    private String name = "";
    private Team team;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy=GenerationType.AUTO)
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }


    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setTeam(Team team) {
        this.team = team;
    }

    @ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "team_id")
    public Team getTeam() {
        return team;
    }

}

使用HQL选择提取集合失败

0 个答案: