Java 限制儿童的休眠标准
我上了一堂简单的课Java 限制儿童的休眠标准,java,mysql,hibernate,spring-boot,Java,Mysql,Hibernate,Spring Boot,我上了一堂简单的课 @Entity(name = "tag") public class Tag { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id") protected long id; @Column(name = "tag", nullable = false) private String tag; public Tag()
@Entity(name = "tag")
public class Tag
{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
protected long id;
@Column(name = "tag", nullable = false)
private String tag;
public Tag()
{
}
public long getId()
{
return id;
}
public void setId(long id)
{
this.id = id;
}
public String getTag()
{
return tag;
}
public void setTag(String tag)
{
this.tag = tag;
}
}
它作为列表驻留在另一个类中,并通过
@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinTable(name = "entry_tag_list", joinColumns = {
@JoinColumn(referencedColumnName = "id", nullable = false)}, inverseJoinColumns = {
@JoinColumn(referencedColumnName = "id", nullable = false)})
@Fetch(FetchMode.SELECT)
private List<Tag> tags;
我明白了
我确保我的getter和setter是getTags和setTags,所以我不确定我遗漏了什么
作为旁注,我必须使用@Fetch(FetchMode.SELECT)
,因为很多查询都依赖于它。像这样试试
cr.createAlias("tags", "tagsAlias");
cr.add(Restrictions.eq("tagsAlias.tag", tag);
像这样试试
cr.createAlias("tags", "tagsAlias");
cr.add(Restrictions.eq("tagsAlias.tag", tag);
您需要创建一个联接以在关联中导航,如标准javadoc中所述。您需要创建一个联接以在关联中导航,如标准javadoc中所述。要创建联接,需要生成别名。要创建联接,需要生成别名。
cr.createAlias("tags", "tagsAlias");
cr.add(Restrictions.eq("tagsAlias.tag", tag);