休眠更新一对多项目集

Question

• 销售订单实体。

  @Entity
  @Table(name = "sales_orders")
  @IdClass(ReceiptPK.class)
  public class SalesOrders implements Serializable {
  
      public SalesOrders() {
      }
      @Id
      protected Integer receiptID;
      @Id
      protected Integer dateKey;
  
      public SalesOrders(Integer receiptID, Integer dateKey) {
          this.receiptID = receiptID;
          this.dateKey = dateKey;
      }
  //order contains many details
  @OneToMany(fetch = FetchType.LAZY, mappedBy = "salesOrders")
  @Cascade({CascadeType.SAVE_UPDATE, CascadeType.DELETE})
  private Set<SalesOrderDetails> orderDetails = new HashSet<SalesOrderDetails>();
  
  public Set<SalesOrderDetails> getOrderDetails() {
      return orderDetails;
  }
  
  public void setOrderDetails(Set<SalesOrderDetails> orderDetails) {
      this.orderDetails = orderDetails;
  }
  // other property ..
  

• 订单详情实体。

  @Entity
  @Table(name = "sales_order_details")
  public class SalesOrderDetails implements Serializable {
  
      public SalesOrderDetails() {
      }
      private int id;
  
      @Id
      @GeneratedValue(strategy = GenerationType.AUTO)
      public int getId() {
          return id;
      }
  
      public void setId(int id) {
          this.id = id;
      }
  
      // Order holder
      private SalesOrders salesOrders;
  
      @ManyToOne
      @JoinColumns({
          @JoinColumn(name = "order_num", referencedColumnName = "receiptID"),
          @JoinColumn(name = "date_key", referencedColumnName = "dateKey")})
      public SalesOrders getSalesOrders() {
          return salesOrders;
      }
  
      public void setSalesOrders(SalesOrders salesOrders) {
          this.salesOrders = salesOrders;
      }
       // other property ...
  

我的问题：当我尝试删除不影响sales_order_details 的订单商品时。

            SalesOrders saleOrder = (SalesOrders) getSession().get(SalesOrders.class ,new ReceiptPK(receiptID,dateKey));
            saleOrder.getOrderDetails().remove(someDetails);
            getSession().beginTransaction();
            getSession().saveOrUpdate(saleOrder);
            getSession().getTransaction().commit();  

但someDetails 没有被删除。

-- 任何帮助将不胜感激...

Answer 1

我认为你必须提交相同的事务。

getSession().getTransaction().begin();
getSession().saveOrUpdate(saleOrder);
getSession().getTransaction().commit();

Answer 2

对于双向关联，您应该（必须）始终确保关联设置正确。

• 不允许直接访问您的收藏。
• 提供修改的添加和删除方法。

---

public Set<SalesOrderDetails> getOrderDetails() {
  //force to use add/remove to ensure consistent object model
  return Collections.unmodifiableSet(orderDetails);
}

public void addOrderDetails(SalesOrderDetails salesOrderDetails){
 orderDetails.add(salesOrderDetails);
 salesOrderDetails.setSalesOrders(this); //important
}

public void removeOrderDetails(SalesOrderDetails salesOrderDetails){
 orderDetails.remove(salesOrderDetails);
 salesOrderDetails.setSalesOrder(null); //important
}

此外，您是否在您的实体上实现了 equals() 和 hashCode()，即当您调用 salesOrder.getOrderDetails().remove(someDetails) 时，实际上是否从集合中删除了任何内容？

如果您没有在 SalesOrderDetails 上实现 equals() 和 hashCode()，则可能不会。

最后，您大喊将 OneToMany 映射上的 orphanRemoval 标志设置为 true：

http://en.wikibooks.org/wiki/Java_Persistence/Relationships#Orphan_Removal_.28JPA_2.0.29