java – hibernate更新JPA外键

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public class TESTClass implements Serializable {

    ...

    private String name;

    @EmbeddedId
    protected IssTESTPK issTESTPK;

    @ManyToOne(optional=false)
    @JoinColumns({
        @JoinColumn(name="DIVISION_CODE",referencedColumnName="DIVISION_CODE",nullable=false,insertable=false,updatable=false),@JoinColumn(name="SURVEY_NUM",referencedColumnName="SURVEY_NUM",updatable=false)})
    private IssDivision issDivision;

}

如果我更改为’name’并调用merge,它可以更新到数据库,但是当我更改issDivision并调用merge时,它不会更新数据库. X- 20045 X- 20045 X- 20045 X- 20045 200:

这是否与我使用embededId(复合主键)相关?

更新

如果我设置upadted = true,我得到以下错误

ERROR - ContextLoader.initWebApplicationContext(215) | Context initialization fa
iled
org.springframework.beans.factory.BeanCreationException: Error creating bean wit
h name 'sessionFactory' defined in ServletContext resource [/WEB-INF/application
Context.xml]: Invocation of init method Failed; nested exception is org.hibernat
e.MappingException: Repeated column in mapping for entity: com.compay.test.model
.TESTClass column: SURVEY_NUM (should be mapped with insert="false" update="fa
lse")
        at org.springframework.beans.factory.support.AbstractAutowireCapableBean
Factory.initializeBean(AbstractAutowireCapablebeanfactory.java:1338)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBean
Factory.doCreateBean(AbstractAutowireCapablebeanfactory.java:473)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBean
Factory$1.run(AbstractAutowireCapablebeanfactory.java:409)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBean
Factory.createBean(AbstractAutowireCapablebeanfactory.java:380)
        at org.springframework.beans.factory.support.Abstractbeanfactory$1.getOb
ject(Abstractbeanfactory.java:264)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistr
y.getSingleton(DefaultSingletonBeanRegistry.java:222)
        at org.springframework.beans.factory.support.Abstractbeanfactory.doGetBe
an(Abstractbeanfactory.java:261)
        at org.springframework.beans.factory.support.Abstractbeanfactory.getBean
(Abstractbeanfactory.java:185)
        at org.springframework.beans.factory.support.Abstractbeanfactory.getBean
(Abstractbeanfactory.java:164)
        at org.springframework.beans.factory.support.DefaultListablebeanfactory.
preInstantiateSingletons(DefaultListablebeanfactory.java:423)
        at org.springframework.context.support.AbstractApplicationContext.finish
beanfactoryInitialization(AbstractApplicationContext.java:728)
        at org.springframework.context.support.AbstractApplicationContext.refres
h(AbstractApplicationContext.java:380)
        at org.springframework.web.context.ContextLoader.createWebApplicationCon
text(ContextLoader.java:255)
        at org.springframework.web.context.ContextLoader.initWebApplicationConte
xt(ContextLoader.java:199)
        at org.springframework.web.context.ContextLoaderListener.contextInitiali
zed(ContextLoaderListener.java:45)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContex
t.java:3843)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4
342)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase
.java:791)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:77
1)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)

        at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.ja
va:627)
        at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.j
ava:553)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:488
)
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1149)
        at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java
:311)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(Lifecycl
eSupport.java:117)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)

        at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)

        at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443
)
        at org.apache.catalina.core.StandardService.start(StandardService.java:5
16)
        at org.apache.catalina.core.StandardServer.start(StandardServer.java:710
)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.

解决方法

好吧,我们来看看

你的例外(和着名的)消息是

repeated column in mapping for entity:
column: SURVEY_NUM (should be mapped with insert="false" update="false")

SURVEY_NUM列在哪里?

1ºissDivision字段存储一个名为SURVEY_NUM的外键列

@ManyToOne
@JoinColumns({
    @JoinColumn(name="DIVISION_CODE",updatable=false)})
private IssDivision issDivision;

现在,请看下面的映射(请参阅id和accountNumber共享相同的列)

@Entity
public class Account {

    private Integer id;

    private Integer accountNumber;

    @Id
    @Column(name="ACCOUNT_NUMBER")
    public Integer getId() {
        return this.id;
    }

    @Column(name="ACCOUNT_NUMBER")
    public Integer getAccountNumber() {
        return this.accountNumber;
    }

}

现在我们来做如下

Account account = new Account();
account.setId(127359);
account.setAccountNumber(null);

entityManager.persist(account);

Hibernate会问你

Which property should i persist whether both properties shares the same column ??? And as i can see,id property stores a non-null value and accountNumber a null value.

我应该像这样执行一个查询吗?

INSERT INTO ACCOUNT (ACCOUNT_NUMBER,ACCOUNT_NUMBER) VALUES (127359,NULL);

它没有任何意义.因此,这是一个错误SQL查询;

因为这样,你看到这个好消息

repeated column… blah,blah,blah… (should be mapped with insert=”false” update=”false”)

所以我想你的复合主键称为IssTESTPK也存储一个名为SURVEY_NUM的列.而且您将复合主键属性定义为insert =“false”update =“false”并不是个好主意.避免很多头痛.

请记住:当多个属性共享同一列时,将其中的一个定义为insertable = false,updatable = false.没有其他的.

我认为你的复合主键类应该是这样的

@Embeddable
public class IssTESTPK implements Serializable {

    // Ops... Our missing field which causes our Exception (repeated column... blah,blah...)
    @Column(name="SURVEY_NUM",nullable=false)
    private Integer property;

    private Integer otherProperty;

    private Integer anotherProperty;

    // required no-arg constructor
    public IssTESTPK() {}

    // You must implement equals and hashcode
    public boolean equals(Object o) {
        if(o == null)
            return false;

        if(!(o instanceof IssTESTPK))
            return false;

        IssTESTPK other = (IssTESTPK) o;
        if(!(getProperty().equals(other.getProperty())))
            return false;
        if(!(getOtherProperty().equals(other.getOtherProperty())))
            return false;
        if(!(getAnotherProperty().equals(other.getAnotherProperty())))
            return false;

        return true;
    }

    // NetBeans or Eclipse will worry about it
    public int hashcode() {
        // hashcode code goes here
    }

}

UPDATE

在继续之前

Hibernate does not support automatic generation of compound primary key

保存前必须提供其值.记住它

我们来看看员工复合主键

@Embeddable
public class EmployeeId implements Serializable {

    @Column(name="EMPLOYEE_NUMBER")
    private String employeeNumber;

    @Column(name="SURVEY_NUMBER")
    private BigInteger surveyNumber;

    // getter's and setter's

    // equals and hashcode

}

1º在保存员工之前,您必须提供其值.如上所述,Hibernate不支持复合主键的自动生成

2ºHibernate不允许您更新(复合)主键没有意义.

3º其值不能为空

所以,如上所述,我们的EmployeeId可以写成

@Embeddable
public class EmployeeId implements Serializable {

    @Column(name="EMPLOYEE_NUMBER",updatable=false)
    private String employeeNumber;

    @Column(name="SURVEY_NUMBER",updatable=false)
    private BigInteger surveyNumber;

    // getter's and setter's

    // equals and hashcode

}

如上所述

when more than one property shares the same column,define one of them as insertable=false,updatable=false. Nothing else

但是我们不能将复合主键属性标记为insertable = false,updatable = false,因为Hibernate使用它来保存我们的实体

由于Hibernate将使用名为surveyNumber(及其SURVEY_NUMBER列)的复合主键属性来对数据库执行sql操作,因此我们需要将@ManyToOne除法属性(及其外键列名为SURVEY_NUMBER)重写为可插入= false,可更新= FALSE

// Employee.java

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns({
    @JoinColumn(name="DIVISION_CODE",referencedColumnName="DIVISION_CODE"),@JoinColumn(name="SURVEY_NUMBER",referencedColumnName="SURVEY_NUMBER",updatable=false)})
private Division division;

4º当您有复合外键时,我们无法混合可插入或不可更新 – 不可更新.

就像是

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns({
    // I can be updatable
    @JoinColumn(name="DIVISION_CODE",insertable=false),// And i can be insertable
    @JoinColumn(name="SURVEY_NUMBER",updatable=false)})
private Division division;

否则,Hibernate会抱怨

Mixing insertable and non insertable columns in a property is not allowed

因此,名为DIVISION_CODE的复合外键列也应标记为insertable = false,updatable = false以避免上述异常

// Employee.java

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns({
    @JoinColumn(name="DIVISION_CODE",updatable=false)})
private Division division;

由于我们无法更新DIVISION_CODE列,我们的division属性的行为就像一个常量.那么,您可以想像创建一个名为divisionCode的新属性来改变DIVISION_CODE列,如下所示

// Employee.java

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns({
    @JoinColumn(name="DIVISION_CODE",updatable=false)})
private Division division;

// Wow,now i expect i can change the value of DIVISION_CODE column
@Column(name="DIVISION_CODE")
private BigInteger divisionCode;

好吧,我们来看看.假设我们有以下DIVISION TABLE

DIVISION TABLE
DIVISION_CODE     SURVEY_NUMBER
1                 10
2                 11
3                 12
4                 13
5                 14

记住:Division和Employee之间有一个外键约束

你想到了

I can not change division property because of insertable=false,updatable=false. But i can change divisionCode property (and its DIVISION_CODE column) as a way to change the foreign key column called DIVISION_CODE

您执行以下代码

employee.setDivisionCode(7);

哇,见上面的DIVISION_TABLE. DIVISION_CODE列中的某些值是否等于7?

答案很清楚:否(你会看到约束违规)

所以,这是一个不一致的映射. Hibernate不允许.

问候,

原文链接:https://www.f2er.com/java/122470.html

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