java 休眠一对多插入
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Hibernate one to many insert
提问by Mitja Rogl
As you can see I have two tables(Offer,Items) I have a problem with inserting Items,every time I add Offer it does not insert List of Items. Offer holds a list of items. Here is my code:
如您所见，我有两个表（Offer、Items），我在插入项目时遇到问题，每次添加 Offer 时，它都不会插入项目列表。Offer 包含一个项目列表。这是我的代码：
OFFER:
提供：
@Entity
public class Offer{
@Id
@GeneratedValue
int id;
private String name;
private String description;
@OneToMany(mappedBy="offer")
private List<Item> items;
//getters and setters
ITEMS:
项目：
@Entity
public class Item{
@Id
@GeneratedValue
int idItem;
private String name;
private double price;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="idOffer")
private Offer offer;
// getters and setters
AND HERE IS CODE FOR FILLING TABLES:
这是填充表格的代码：
Offer offer=GenerateData.generateOffer();
List<Item> items=new ArrayList<>();
for(int i=0;i<3;i++){
Item item=GenerateData.generateItem();
items.add(item);
item.setOffer(offer);
}
offer.setItems(items);
pDB.addOffer(offer);//DAO for adding Offers into DB
Offer is successfully added, but Items are not. Is it problem with mapping?
优惠已成功添加，但商品未成功添加。映射有问题吗？
回答by Farzad
did you try putting a cascade option on the OneToMany side?
您是否尝试在 OneToMany 端放置级联选项？
回答by Kent
Offer
提供
@OneToMany(cascade = { CascadeType.ALL }, orphanRemoval = true, mappedBy = "offer")
private List<Item> items;
Item:
物品：
@ManyToOne
@JoinColumn(name="idOffer")
private Offer offer;
