OneToOne annotation级联更新及新增

前些天在做项目的时候需要用到Hibernate的级联保存和更新，出现了几个错误，已经解决了这里记上一笔。

首先是实例：

 

@Entity
@Table(name = "tbl_order")
public class Order {
	
	@Id
	@GeneratedValue(generator = "ORDER_ID")
	@GenericGenerator(strategy = "assigned", name = "ORDER_ID")
	private Integer id;
	
	@OneToOne
	@JoinColumn(name = "orderId")
	private OperationTime operationTimes;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public OperationTime getOperationTimes() {
		return operationTimes;
	}

	public void setOperationTimes(OperationTime operationTimes) {
		this.operationTimes = operationTimes;
	}
}


@Entity
@Table(name = "tbl_order_extension")
public class OperationTime {

	@Id
	@GeneratedValue(generator = "ORDER_ID")
	@GenericGenerator(strategy = "assigned", name = "ORDER_ID")
	private Integer orderId;
	
	@Column(name = "apply_time")
	private Date applyTime;
	
	@Column(name = "accept_time")
	private Date acceptTime;
	
	@OneToOne
	@JoinColumn(name = "id")
	private Order order;

	public Integer getOrderId() {
		return orderId;
	}

	public void setOrderId(Integer orderId) {
		this.orderId = orderId;
	}

	public Date getApplyTime() {
		return applyTime;
	}

	public void setApplyTime(Date applyTime) {
		this.applyTime = applyTime;
	}

	public Date getAcceptTime() {
		return acceptTime;
	}

	public void setAcceptTime(Date acceptTime) {
		this.acceptTime = acceptTime;
	}

	public Order getOrder() {
		return order;
	}

	public void setOrder(Order order) {
		this.order = order;
	}
}

 

 Order和OperationTime是一对一的映射关系，在级联保存的时候需要这样写：

 

public void saveOrder(Order order){
        //business code
       OperationTime operationTimes = new OperationTime();
       operationTimes.setApplyTime(new Date());
       operationTimes.setOrder(order);
       //operationTimes.setOrderId(order.getId());     a
       order.setOperationTimes(operationTimes);
       orderDao.save(order);
}

 

 千万不能像a处给operationTimes.orderId赋值，因为如果在这里能取到值Hibernate会默认执行update语句这样就会出现错误。

Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1 

但是不赋值我的副类主键是需要分配的，且是主键关联，需要将其主键生成策略做下修改。

 

        @Id
	@GeneratedValue(generator = "foreign")
	@GenericGenerator(name = "foreign", strategy = "foreign", 
			parameters = { 
				@Parameter(name = "property", value = "order") 
			})
	private Integer orderId;

 

同理在更新的时候一定别忘了为operationTimes.orderId赋值，否则将会执行create语句。因为我这里是分配的主键策略是assigned的会报ids must be manually assigned