JPA配置一对多双向并且外键中含联合主键

最新推荐文章于 2022-02-21 10:36:51 发布

原创最新推荐文章于 2022-02-21 10:36:51 发布 · 1.1w 阅读

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CC 4.0 BY-SA版权

本文介绍了一种使用Java与JPA实现一对多关系及复合主键的方法。通过示例展示了如何定义实体类、复合主键类以及设置关联关系。

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关于一对多映射，并且多的一方主键为复合主键

完整code如下

1.主体类

@Entity
@Table(name="INFO_GRP")
public class InfoGrp extends GenericBean implements IDataObject{
	
	private static final long serialVersionUID = 1918446199175160468L;
	
	@Id
	@Column(name = "grpId", unique=true, nullable = false, columnDefinition = "varchar(10)")
	private String grpId;
	
	@Column(name = "grpname",  nullable = true, columnDefinition = "varchar(75)")
	private String grpName;
	
	@Column(name = "creator", nullable = true, columnDefinition = "varchar(10)")
	private String creator;
	
	@Column(name = "createTime",nullable = true)
	@Temporal(TemporalType.TIMESTAMP)
	private Date createTime;
	
	@Column(name = "updater",  nullable = true, columnDefinition = "varchar(10)")
	private String updater;
	
	@Column(name = "updateTime",nullable = true)
	@Temporal(TemporalType.TIMESTAMP)
	private Date updateTime;
	
	@Column(name = "deleted",  nullable = true, columnDefinition = "varchar(1)")
	private String deleted;
	
	@Column(name = "isApprove",  nullable = true, columnDefinition = "varchar(1)")
	private String isApprove;

	 @OneToMany(cascade=CascadeType.ALL,fetch=FetchType.EAGER,mappedBy="id.infoGrp")
	 private Set<InfoGrpPermission> infoGrpPermissions = new HashSet<InfoGrpPermission>();
	}

关联的多的一方的对象如下：

@Entity
@Table(name="INFO_GRP_PERMISSION")
public class InfoGrpPermission extends GenericBean implements IDataObject{
	
	private static final long serialVersionUID = 1918446199175160468L;
	
	@EmbeddedId
	private InfoGrpPermissionId id;
	
	@Column(name = "creator",  nullable = true, columnDefinition = "varchar(10)")
	private String creator;
	
	@Column(name = "createTime",nullable = true)
	@Temporal(TemporalType.TIMESTAMP)
	private Date createTime;
	
	@Column(name = "updater", columnDefinition = "varchar(10)")
	private String updater;
	
	@Column(name = "updateTime",nullable = true)
	@Temporal(TemporalType.TIMESTAMP)
	private Date updateTime;
	
	@Column(name = "deleted",  nullable = true, columnDefinition = "varchar(1)")
	private String deleted;
}

复合主键编写如下：

@Embeddable
public class InfoGrpPermissionId implements Serializable{
	
	private static final long serialVersionUID = 1918446199175160468L;
	@ManyToOne(cascade=CascadeType.ALL,fetch=FetchType.EAGER)
	@JoinColumn(name = "grpId",  nullable = false, columnDefinition = "varchar(10)")
	private InfoGrp infoGrp;
	@Column(name = "permission",  nullable = false, columnDefinition = "varchar(10)")
	private String permission;}

其中的get和set方法均省略。