休眠 select 来自 child table 的查询

Question

我对休眠还很陌生。我有两个 table 具有 一对多 关系。两个 table 是：

public class Pashmina implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "sq_pashmina_id")
    @SequenceGenerator(name = "sq_pashmina_id", sequenceName = "sq_pashmina_id")
    @Column(name = "PASHMINA_ID")
    private int pashminaId;

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

    @Column(name = "PRICE")
    private double price;

    @Column(name = "ADDED_AT", insertable = false)
    @Temporal(TemporalType.TIMESTAMP)
    private Date addedAt;

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

    @Column(name = "ENABLED", insertable = false)
    private Character enabled;

    @OneToMany(mappedBy = "colourId", fetch = FetchType.EAGER)
    private Set<PashminaColour> pashminaColor  = new HashSet<PashminaColour>();

    @OneToMany(mappedBy = "imageId", fetch = FetchType.EAGER)
    private Set<Image> images  = new HashSet<Image>();

    @OneToMany(mappedBy = "descriptionId", fetch = FetchType.EAGER)
    private Set<Description> descriptions  = new HashSet<Description>();

    //getter and setter method

这是一个 parent class 并且它与图像具有一对多关系 table

public class Image implements Serializable {
    @Id
    @Column(name = "IMAGE_ID")
    private int imageId;

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

    @JoinColumn(name = "PASHMINA_ID", referencedColumnName = "PASHMINA_ID")
    @ManyToOne
    private Pashmina pashmina;

现在我想 select 来自 Image class 的 imagenames 使用其 parent class 的 ID（即：pashminaId )

例如：

SELECT IMAGE_NAME FROM TBL_IMAGE WHERE PASHMINA_ID = 'some_digit';

我如何在图像 class 中传递 pashminaId 因为没有 pashminaId 它只有 Object 创建 Parent class Pashmina.

那么，我如何在休眠中实现这个？

如果你不明白我的意思，请告诉我。

谢谢！希望积极响应。

Answer 1

由于 Hibernate 处理对象而不是 SQL 表，您可以简单地从 image 对象访问 pashmina 对象，并且在您的查询中您将处理 java objects/POJOs，因此您可以通过 Image.pashmina.pashminaId.

访问它

所以你可以编写如下查询：

String hql = "select I.imageName FROM Image I WHERE I.pashmina.pashminaId = 10";
Query query = session.createQuery(hql);
List results = query.list();

休眠 select 来自 child table 的查询

hibernate select query from child table

java

hibernate

hql

spring-mvc

hibernate-mapping

如果你不明白我的意思，请告诉我。