[英]Many-to-Many Association with Extra Columns
I am not able to map correctly even following all the steps provided in: https://www.mkyong.com/hibernate/hibernate-many-to-many-example-join-table-extra-column-annotation/ 即使执行以下所有步骤,我也无法正确映射: https : //www.mkyong.com/hibernate/hibernate-many-to-many-example-join-table-extra-column-annotation/
CREATE TABLE `tb_pla_playlist` (
`id_playlist` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`nm_playlist` VARCHAR(10) NOT NULL,
PRIMARY KEY (`id_playlist`) USING BTREE,
)
CREATE TABLE `tb_mid_midia` (
`id_midia` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`nm_midia` VARCHAR(10) NOT NULL,
PRIMARY KEY (`id_midia`) USING BTREE
)
CREATE TABLE `tb_mip_midia_playlist` (
`id_midia` INT(10) UNSIGNED NOT NULL,
`id_playlist` INT(10) UNSIGNED NOT NULL,
`nr_ordem` INT(10) UNSIGNED NOT NULL,
`CREATED_BY` VARCHAR(10) NOT NULL,
PRIMARY KEY (`id_midia`,`CATEGORY_ID`),
CONSTRAINT `FK_id_midia` FOREIGN KEY (`id_midia`)
REFERENCES `midia` (`id_midia`),
CONSTRAINT `FK_id_playlist` FOREIGN KEY (`id_playlist`)
REFERENCES `playlist` (`id_playlist`)
)
playlist.java 播放列表
@Entity
@Table(name="tb_pla_playlist")
public class Playlist implements Serializable {
private Set<MidiaPlaylist> midiaPlaylist = new HashSet<MidiaPlaylist>();
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="id_playlist")
private Long idPlaylist;
@OneToMany(mappedBy = "id.playlist", cascade = CascadeType.ALL)
private Set<MidiaPlaylist> getMidiaPlaylist(){
return midiaPlaylist;
}
...
}
[erro: In attribute 'midiaPlaylist', the "mapped by" value 'id.playlist' cannot be resolved to an attribute on the target entity.] [错误:在属性“ midiaPlaylist”中,“映射人”值“ id.playlist”无法解析为目标实体上的属性。
midia.java midia.java
@Entity
@Table(name="tb_mid_midia")
public class Midia implements Serializable {
private Set<MidiaPlaylist> midiaPlaylist = new HashSet<MidiaPlaylist>();
@Id
@GeneratedValue
@Column(name="id_midia")
private Long idMidia;
@OneToMany(mappedBy = "id.midia", cascade=CascadeType.ALL)
public Set<MidiaPlaylist> getMidiasPlaylist() {
return midiaPlaylist;
}
[erro: In attribute 'midiasPlaylist', the "mapped by" value 'id.midia' cannot be resolved to an attribute on the target entity.] [错误:在属性“ midiasPlaylist”中,“映射人”值“ id.midia”无法解析为目标实体上的属性。
MidiaPlaylistPK.java MidiaPlaylistPK.java
@Embeddable
public class MidiaPlaylistPK implements Serializable {
private Midia midia;
private Playlist playlist;
@ManyToOne(cascade = CascadeType.ALL)
public Midia getMidia(){
return midia;
}
public void setMidia(Midia midia){
this.midia = midia;
}
@ManyToOne(cascade = CascadeType.ALL)
public Playlist getPlaylist(){
return playlist;
}
public void setPlaylist(Playlist playlist){
this.playlist = playlist;
}
}
MidiaPlaylist.java MidiaPlaylist.java
@Entity
@Table(name="tb_mip_midia_playlist")
@AssociationOverrides({
@AssociationOverride(name="id.playlist", [erro: Persistent type of override attribute "id.playlist" cannot be resolved]
joinColumns = @JoinColumn(name = "id_playlist")),
@AssociationOverride(name="id.midia", [erro: Persistent type of override attribute "id.midia" cannot be resolved]
joinColumns = @JoinColumn(name = "id_midia"))
})
public class MidiaPlaylist implements Serializable {
private MidiaPlaylistPK id = new MidiaPlaylistPK();
private int nrOrdem;
@EmbeddedId [erro: Embedded ID class should not contain relationship mappings]
public MidiaPlaylistPK getId() {
return this.id;
}
@Column(name="nr_ordem", nullable=false)
public int getNrOrdem(){
return this.nrOrdem;
}
@Transient
public Midia getMidia(){
return getId().getMidia();
}
@Transient
public Playlist getPlaylist(){
return getId().getPlaylist();
}
Can someone help me with these errors? 有人可以帮助我解决这些错误吗? Ty!
!
您应该删除@ManyToOne
@ManyToOne @Embeddable
并使用@Transient
@MapId
注释,这里有一个示例: http ://www.objectdb.com/api/java/jpa/MapsId
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.