Hibernate 多对多关系数据插入？

Question

我的项目包含一个卡片实体和一个用户实体，它们之间存在多对多的关系。将用户对象插入卡片对象时，它不会将数据插入数据库的 user_card 表中。

//控制器

    @PostMapping(value = "create")
public Card create( @RequestBody JSONObject data){
    Card card = new Card();
    String name =(String) data.get("name");
    Long columnId = Long.valueOf((Integer)data.get("columnId"));
    Long ownerId = Long.valueOf((Integer)data.get("ownerId"));
    Integer  cardOrder = Integer.valueOf((Integer)data.get("cardOrder"));
    String lastDate =(String) data.get("lastDate");
    String description =(String) data.get("description");
    String assignedUsersId= (String)(data.get("assignedUsers"));
    String[] assignedUsersIdArray=assignedUsersId.split(",");
    List<User> assignedUsers = new ArrayList<>();

    for(int i=0;i<assignedUsersIdArray.length  ;i++){
        String id = assignedUsersIdArray[i];
        if(!id.equals("")) {
            assignedUsers.add(userService.getOne(Long.parseLong(id)));
        }
    }

    card.setName(name);
    card.setColumnId(columnId);
    card.setOwnerId(ownerId);
    card.setCardOrder(cardOrder);
    card.setLastDate(lastDate);
    card.setDescription(description);
    card.setUsers(assignedUsers);

    return cardService.save(card);
}

//用户实体

@LazyCollection(LazyCollectionOption.FALSE)
@ManyToMany(cascade = {CascadeType.ALL})
@JoinTable(
        name = "user_card",
        joinColumns = {@JoinColumn(name = "userid")},
        inverseJoinColumns = {@JoinColumn(name="cardid")}
)
@JsonIgnoreProperties("users")
private List<Card> cards = new ArrayList<>();

public List<Card> getCards() {
    return cards;
}

//卡片实体

    @ManyToMany(mappedBy = "cards")
@JsonIgnoreProperties("cards")
private List<User> users = new ArrayList<>();
//    @JsonManagedReference

public void setUsers(List<User> users) {
    for(User user : users){
        this.users.add(user);
    }


}
public List<User> getUsers() {
    return users;
}

Answer 1

您应该将cascade 移动到卡片实体。由于您希望插入卡片触发插入用户，而不是其他方式。