在休眠狀態下以一對多關係從父表中刪除記錄

Question

我有以下情況： 客戶的一個表可以有許多項目。這種關係是雙向的。

我試圖刪除客戶列表的客戶，如果客戶已經有一些項目分配我有一個例外：

" that I cannot delete or update a parent row: a foreign key constraint fails"

這意味着我必須先刪除相關的項目。

但是我需要一個解決方案，我想這個問題與映射文件有關。以下是映射文件：

<hibernate-mapping> 
<class name="com.nisid.entities.Customers" table="customers"> 
<meta attribute="class-description"> This class contains the customer records. </meta> 
<id name="customerId" type="int" column="customerId"> 
    <generator class="native"/> 
</id> 
<many-to-one name="fkuser" class="com.nisid.entities.Worker" 
     fetch="select"> 
     <column name="fk_userID" not-null="true"/> 
</many-to-one> 
<set name="projects" lazy="false" inverse="true" fetch="select" cascade="all" > 
<key column="customerId" not-null="true"/> 
<one-to-many class="com.nisid.entities.Project"/> 
</set> 

<property name="customerName" column="customerName" type="string"/> 
<property name="customerSurname" column="customerSurname" type="string"/> 
<property name="adress" column="adress" type="string"/> 
<property name="email" column="email" type="string"/> 
<property name="phoneNumber" column="contactDetails" type="string"/> 

</class> 


</hibernate-mapping> 

而且孩子：

<hibernate-mapping> 
<class name="com.nisid.entities.Project" table="projects"> 
<meta attribute="class-description"> This class contains the project records. </meta> 
<id name="projectId" type="int" column="projectId"> 
    <generator class="native"> 

    </generator> 
</id> 

<many-to-one name="fkCustomer" class="com.nisid.entities.Customers" 
     fetch="select"> 
     <column name="customerId" not-null="true"/> 
</many-to-one> 


<set name="payments" lazy="true" fetch="select" inverse="true" > 
<key column="projectId" not-null="true"/> 
<one-to-many class="com.nisid.entities.Payment"/> 
</set> 


<property name="projectName" column="projectName" type="string" /> 
<property name="projectDescription" column="description" type="string"/> 


</class> 


</hibernate-mapping> 

Answer 1

變化您的項目級聯設置爲「全刪除，孤兒」，而不是「所有」