针对关系 table 的 Hibernate 查询

Hibernate query targetting a relation table

我正在使用 Hibernate 对 2 table 进行建模,通过关系 table 连接,内部变量如下:

// Clinic.java

@Entity
@Table(name = "clinic")
public class Clinic
{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private long id;

    @Column(name = "name")
    private String name;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.clinic", cascade = CascadeType.ALL)
    private Set<ClinicDoctor> clinicDoctors = new HashSet<ClinicDoctor>(0);

    public long getId()
    {
        return id;
    }

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

    public String getName()
    {
        return name;
    }

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

    @JsonIgnore
    public Set<ClinicDoctor> getClinicDoctors()
    {
        return clinicDoctors;
    }

    public void setClinicDoctors(Set<ClinicDoctor> clinicDoctors)
    {
        this.clinicDoctors = clinicDoctors;
    }
}

// Doctor.java

@Entity
@Table(name = "doctor")
public class Doctor
{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private long id;

    @Column(name = "name", nullable = false)
    private String name;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.doctor", cascade = CascadeType.ALL)
    private Set<ClinicDoctor> clinicDoctors = new HashSet<ClinicDoctor>(0);

    public long getId()
    {
        return id;
    }

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

    public String getName()
    {
        return name;
    }

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

    @JsonIgnore
    public Set<ClinicDoctor> getClinicDoctors()
    {
        return clinicDoctors;
    }

    public void setClinicDoctors(Set<ClinicDoctor> clinicDoctors)
    {
        this.clinicDoctors = clinicDoctors;
    }
}

// 诊所医生

@Entity
@Table(name = "clinic_doctor")
@AssociationOverrides({ @AssociationOverride(name = "pk.clinic", joinColumns = @JoinColumn(name = "clinic")),
        @AssociationOverride(name = "pk.doctor", joinColumns = @JoinColumn(name = "doctor")) })
public class ClinicDoctor
{
    @EmbeddedId
    private ClinicDoctorId pk = new ClinicDoctorId();

    @Column(name = "attendingHours")
    private String attendingHours;

    public ClinicDoctorId getPk()
    {
        return pk;
    }

    public void setPk(ClinicDoctorId pk)
    {
        this.pk = pk;
    }

    public String getAttendingHours()
    {
        return attendingHours;
    }

    public void setAttendingHours(String attendingHours)
    {
        this.attendingHours = attendingHours;
    }

    // Equals & HashCode
}

// ClinicDoctorId

public class ClinicDoctorId implements Serializable
{
    private static final long serialVersionUID = 5880105185191860784L;

    @ManyToOne
    private Clinic clinic;

    @ManyToOne
    private Doctor doctor;

    public Clinic getClinic()
    {
        return clinic;
    }

    public void setClinic(Clinic clinic)
    {
        this.clinic = clinic;
    }

    public Doctor getDoctor()
    {
        return doctor;
    }

    public void setDoctor(Doctor doctor)
    {
        this.doctor = doctor;
    }

    // Equals & HashCode
}

我想列出诊所名称为 'X' 的所有关系。到目前为止我最好的尝试是:

Criteria criteria = session.createCriteria(ClinicDoctor.class);
criteria.createAlias("pk.clinic", "clinic").add(Restrictions.eq("clinic.name", "X"));
res = new ArrayList<>(criteria.list());

但是,这会导致以下 Hibernate 查询和错误:

Hibernate: 
    select
        this_.clinic as clinic2_1_0_,
        this_.doctor as doctor3_1_0_,
        this_.attendingHours as attendin1_1_0_ 
    from
        clinic_doctor this_ 
    where
        clinic1_.name=?

ERROR: Unknown column 'clinic1_.name' in 'where clause'

老实说,我不知道为什么这是错误的。我相信以前做过这个,但在某个地方有一些我看不到(或理解)的东西阻止了这个查询的工作。有人可以帮助我吗?

编辑:按照下面的建议,我试过这个:

Query query = session.createQuery("SELECT cd FROM ClinicDoctor cd WHERE cd.doctor.name = :docname");
query.setParameter("docname", X);

而且效果很好。但是,我更喜欢基于条件的答案,或者至少是关于为什么我的初始查询不起作用的解释。有什么想法吗?

我首先看到的是

where
        clinic1_.name=?

你在问题中说:

I want to list all relations where the name of the doctor is 'X'.

所以您的查询试图检索 诊所 名称为 'X'

的关系

如果你想第一个试试这个:

Query query = session.createQuery("SELECT cd FROM ClinicDoctor cd WHERE cd.doctor.name = :docname");
query.setParameter("docname", X);