我有兩張相關(guān)的面孔。保存到數(shù)據(jù)庫時(shí)，只有一個(gè)對(duì)象被成功保存。第二個(gè)帶外鍵的不保存。第二個(gè)有外鍵的是 List objects Please help。在這里我添加了cascade = CascadeType.ALL，但它仍然沒有工作@Entity@Table(name = "MyOrder")public class MyOrder { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; @OneToMany(mappedBy = "myOrder") private List<Products> productses;我添加了 fetch = Fetch.LAZY，這也沒有幫助。@Entity@Table(name = "Products")public class Products { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; @ManyToOne @JoinColumn(name = "product_myorder_id") private MyOrder myOrder;在控制器中我填充它： MyOrder myOrder = new MyOrder(); List<Products2> products2s = object.getProductses2(); List<Products> productses = new ArrayList<Products>(); for(int i =0;i<products2s.size();i++){ Products2 products2 = products2s.get(i); Products products = new Products(); products.setName(products2.getName()); products.setWeight(products2.getWeight()); products.setAmount(products2.getAmount()); products.setPrice(products2.getPrice()); productses.add(products); } myOrder.setProductses(productses); //saving serviceClass.createNewOrder(myOrder);服務(wù)等級(jí)： @Repository @Transactional public class MyServiceClass { @Autowired @Qualifier(value = "sessionFactory") SessionFactory session; public boolean createNewOrder(MyOrder myOrder){ session.getCurrentSession().save(myOrder); return true; }}
2 回答
慕尼黑5688855
TA貢獻(xiàn)1848條經(jīng)驗(yàn) 獲得超2個(gè)贊
您應(yīng)該考慮以下映射：
將 Long 用于 id 列，而不是 int - int 太小
雙向映射可能更好
有用于添加/刪除孩子的實(shí)用方法（如下面的代碼）
在實(shí)體類中初始化您的集合以避免空值
例子：
@Entity(name = "MyOrder")
@Table(name = "myorder")
public class MyOrder {
@Id
@GeneratedValue
private Long id;
@OneToMany(mappedBy = "myorder", cascade = CascadeType.ALL, orphanRemoval = true)
private List<Product> products = new ArrayList<>();
//Constructors, getters, setters etc.
public void addProduct(Product product) {
products.add(product);
product.setMyOrder(this);
}
public void removeProduct(Product product) {
products.remove(product);
product.setMyOrder(null);
}
}
@Entity(name = "Product")
@Table(name = "product")
public class Product {
@Id
@GeneratedValue
private Long id;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "myorder_id")
private MyOrder myOrder;
//Constructors, getters and setters
//equals and hashCode
}
Qyouu
TA貢獻(xiàn)1786條經(jīng)驗(yàn) 獲得超11個(gè)贊
您的更改沒有從父實(shí)體級(jí)聯(lián)到子實(shí)體，您需要將其添加到您的映射中：
@Entity
@Table(name = "MyOrder")
public class MyOrder {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;
@OneToMany(mappedBy = "myOrder", cascade = CascadeType.All)
private List<Products> productses;
使用列名錯(cuò)誤試試這個(gè)：
@ManyToOne
@JoinColumn(name = "myorder_id")
private MyOrder myOrder;
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