处理一对多和多对一映射时出现问题

Question

问题是当我为已经存在的分类添加sous_categorie时会出现异常

java.sql.SQLIntegrityConstraintViolationException： Le champ 'id_cat' ne peut être vide (null(

我使用邮递员来测试API

{
"id_Cat": "1274d819-ca54-455b-b69f-07a3f8b345c0",
"souCatName": "hospitals"
}

类数据库分类

@Entity
@Table(name = "categorie")
public class DBCategorie {
@Id
@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
private String idCat;
private String catName;
@OneToMany(mappedBy = "categorie")
private List<DBSousCategorie> souscategorie;
public DBCategorie() {
}
//getters& setter
public DBCategorie(String idCat, String catName, List<DBSousCategorie> souscategorie) {
super();
this.idCat = idCat;
this.catName = catName;
this.souscategorie = souscategorie;
}
public DBCategorie(String idCat, String catName) {
this.idCat = idCat;
this.catName = catName;
}

类 DBSousCategorie

@Entity
@Table(name = "souscategorie")
public class DBSousCategorie {
@Id
@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
private String idSouCat;
private String souCatName;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="id_Cat")
private DBCategorie categorie;
@OneToMany(mappedBy = "souscategorie")
private List<DBFile> files;
public DBSousCategorie() {
}
//Getters & Setters
public DBSousCategorie(String idSouCat, String souCatName, DBCategorie categorie) {
super();
this.idSouCat = idSouCat;
this.souCatName = souCatName;
this.categorie = categorie;
}

Answer 1

您是否在持久化之前将父分类对象设置为 sous_category？

dbSousCategory.setCategory(categorie);
subCategoryService.save(dbSousCategory);

为了避免递归，请使用@JsonIgnore忽略父类别。

@Entity
@Table(name = "souscategorie")
public class DBSousCategorie {
@Id
@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
private String idSouCat;
private String souCatName;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="id_Cat")
@JsonIgnore
private DBCategorie categorie;
@OneToMany(mappedBy = "souscategorie")
private List<DBFile> files;
public DBSousCategorie() {
}
//Getters & Setters
public DBSousCategorie(String idSouCat, String souCatName, DBCategorie categorie) {
super();
this.idSouCat = idSouCat;
this.souCatName = souCatName;
this.categorie = categorie;
}