Java 与冬眠一起迷失-一个浪漫导致一个被多次拉回
我有这样的DB设计:Java 与冬眠一起迷失-一个浪漫导致一个被多次拉回,java,mysql,hibernate,hibernate-onetomany,Java,Mysql,Hibernate,Hibernate Onetomany,我有这样的DB设计: CREATE TABLE report ( ID MEDIUMINT PRIMARY KEY NOT NULL AUTO_INCREMENT, user MEDIUMINT NOT NULL, created TIMESTAMP NOT NULL, state INT NOT NULL, FOREIGN KEY (user) REFERENCES user(ID) ON UPDATE
CREATE TABLE report (
ID MEDIUMINT PRIMARY KEY NOT NULL AUTO_INCREMENT,
user MEDIUMINT NOT NULL,
created TIMESTAMP NOT NULL,
state INT NOT NULL,
FOREIGN KEY (user) REFERENCES user(ID) ON UPDATE CASCADE ON DELETE CASCADE
);
CREATE TABLE reportProperties (
ID MEDIUMINT NOT NULL,
k VARCHAR(128) NOT NULL,
v TEXT NOT NULL,
PRIMARY KEY(
ID, k
),
FOREIGN KEY (ID) REFERENCES report(ID) ON UPDATE CASCADE ON DELETE CASCADE
);
这是Hibernate标记:
@Table(name="report")
@Entity(name="ReportEntity")
public class ReportEntity extends Report{
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="ID")
private Integer ID;
@Column(name="user")
private Integer user;
@Column(name="created")
private Timestamp created;
@Column(name="state")
private Integer state = ReportState.RUNNING.getLevel();
@OneToMany(mappedBy="pk.ID", fetch=FetchType.EAGER)
@JoinColumns(
@JoinColumn(name="ID", referencedColumnName="ID")
)
@MapKey(name="pk.key")
private Map<String, ReportPropertyEntity> reportProperties = new HashMap<String, ReportPropertyEntity>();
}
我已经插入了报告和该报告的4个属性。现在当我执行此操作时:
this.findByCriteria(
Order.asc("created"),
Restrictions.eq("user", user.getObject(UserField.ID))
)
);
我四次返回报告,而不是一次返回一个包含4个属性的地图。老实说,我并不擅长Hibernate,我更喜欢纯SQL,但我必须学习,但我看不出这是怎么回事
有什么建议吗?我不知道你的问题的答案,但你可以用另一种方式来做,并取消整个
ReportPropertyEntity
类:
@CollectionOfElements
@JoinTable(name = "reportProperties", joinColumns = { @JoinColumn(name = "id") })
@MapKey(columns = { @Column(name = "`key`") })
@Column(name = "`value`", length = 131070, nullable = false)
private Map<String, String> reportProperties = new HashMap<String, String>();
@collectionfements
@JoinTable(name=“reportProperties”,joinColumns={@JoinColumn(name=“id”)})
@MapKey(columns={@Column(name=“`key`”)})
@列(name=“`value`”,长度=131070,null=false)
私有映射reportProperties=newhashmap();
尝试在您的条件/查询中使用此选项:
setResultTransformer(DistinctRootEntityResultTransformer.INSTANCE);
这将适用于您的所有桌子。无需修改映射。这可能不是我所认为的答案,但效果不错。我需要沉迷于冬眠,这会让我的生活更轻松…谢谢!您应该使用@ElementCollection。请参见文档中的:“注意,我们建议您从@org.hibernate.annotations.collectionfelments迁移到新的@ElementCollection注释。”
setResultTransformer(DistinctRootEntityResultTransformer.INSTANCE);