休眠级联在保存时抛出异常答案

【问题标题】：Hibernate cascading throws Exception on save休眠级联在保存时抛出异常
【发布时间】：2013-07-10 17:31:16
【问题描述】：

我正在尝试在数据库中插入一个对象。它包含一个也应该插入的集合，但我得到以下异常：

SQLServerException: Cannot insert the value NULL into column 'ID_CUSTOMER', table 'dbo.CUSTOMER_ADDRESS'; column does not allow nulls. INSERT fails.

映射如下：

CustomerDB.java

@OneToMany(fetch = FetchType.LAZY, mappedBy = "customer", orphanRemoval = true, cascade = CascadeType.ALL)
private List<CustomerAddressDB> addresses;

CustomerAddressDB.java

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.REFRESH)
@JoinColumn(name = "ID_CUSTOMER", nullable = false, updatable=false, insertable=false)
private CustomerDB customer;

所以，当我为 CustomerDB 实体调用 persist 方法时，我可以看到 HQL 正在执行：

Hibernate: insert into M2M_CUSTOMER (NM_COMPANY_NAME, DT_CREATED, ID_PARENT, ID_LAYER, DS_OBS, DS_SHORT_NAME, ID_CUSTOMER_STATUS, NM_TRADING_NAME) values (?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: insert into M2M_CUSTOMER_ADDRESS (DS_CITY, DS_COUNTRY, NR_NUMBER, NR_POSTAL_CODE, DS_STATE, DS_STREET, ID_ADDRESS_TYPE) values (?, ?, ?, ?, ?, ?, ?)

但在此之后会抛出前面提到的异常。我不明白为什么它说 CUSTOMER_ID 为空，因为客户被插入到地址之前。有没有映射错误？

谢谢！

【问题讨论】：

您在客户的“id”字段中有哪些注释？

标签： hibernate jpa-2.0 one-to-many hibernate-mapping cascade

【解决方案1】：

您告诉 Hibernate，不应插入或更新 Address 实体中的客户，因此 Hibernate 不会插入它。替换

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.REFRESH)
@JoinColumn(name = "ID_CUSTOMER", nullable = false, updatable=false, insertable=false)
private CustomerDB customer;

通过

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.REFRESH)
@JoinColumn(name = "ID_CUSTOMER", nullable = false)
private CustomerDB customer;

【讨论】：