java.sql.SQLException：无法添加或更新子行：外键约束失败

Question

当我尝试保留 ServiceProvider 实体时，有人可以帮助我理解为什么会出现以下错误？

java.sql.SQLException: Cannot add or update a child row: a foreign key constraint fails (`springmvc/businesslocation`, CONSTRAINT `FK5CB747B5A26ED80E` FOREIGN KEY (`state_id`) REFERENCES `state` (`id`))
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2975)
 at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
 at com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1129)
 at com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:681)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1368)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1283)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1268)
 at org.apache.commons.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:102)
 at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:72)
 at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:33)
 at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2163)
 at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2643)
 at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:48)
 at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
 at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298)
 at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
 at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:94)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
 at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:511)
 at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:503)
 at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:218)
 at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:268)
 at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:216)
 at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:169)
 at org.hibernate.engine.Cascade.cascadeCollectionElements(Cascade.java:296)
 at org.hibernate.engine.Cascade.cascadeCollection(Cascade.java:242)
 at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:219)
 at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:169)
 at org.hibernate.engine.Cascade.cascade(Cascade.java:130)
 at org.hibernate.event.def.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:456)
 at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:334)
 at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
 at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
 at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
 at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
 at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:539)
 at org.hibernate.impl.SessionImpl.save(SessionImpl.java:527)
 at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
 at org.springframework.orm.hibernate3.HibernateTemplate$12.doInHibernate(HibernateTemplate.java:642)
 at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:373)
 at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:639)
 at com.inception.dao.ServiceProviderDAOImpl.save(ServiceProviderDAOImpl.java:23)
 at com.inception.service.ServiceProviderServiceImpl.addServiceProvider(ServiceProviderServiceImpl.java:21)
 at com.inception.web.RegisterServiceProviderController.processFinish(RegisterServiceProviderController.java:68)
 at org.springframework.web.servlet.mvc.AbstractWizardFormController.validatePagesAndFinish(AbstractWizardFormController.java:642)
 at org.springframework.web.servlet.mvc.AbstractWizardFormController.processFormSubmission(AbstractWizardFormController.java:492)
 at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:265)
 at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
 at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809)
 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:476)
 at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:441)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
 at java.lang.Thread.run(Thread.java:619)

情况如下：一个ServiceProvider有一个BusinessLocation列表，一个State有一个BusinessLocation列表。

在我想要保留的带注释的类之后： 的 ServiceProvider.java

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;

@Entity
public class ServiceProvider implements Serializable{

 private Long id; 
 private Set<BusinessLocation> businessLocations = new HashSet<BusinessLocation>();

 @Id
 @GeneratedValue
 public Long getId() {
  return id;
 }
 public void setId(Long id) {
  this.id = id;
 }

 @OneToMany(mappedBy="serviceProvider", targetEntity=BusinessLocation.class, cascade=CascadeType.ALL, fetch=FetchType.EAGER)
 public Set<BusinessLocation> getBusinessLocations() {
  return businessLocations;
 }

 public void setBusinessLocations(Set<BusinessLocation> businessLocations) {
  this.businessLocations = businessLocations;
 }

}

BusinessLocation，JAVA

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;

@Entity
public class BusinessLocation implements Serializable{

 private Long id;
 private String address;
 private String city;
 private State state;
 private String pincode;
 private ServiceProvider serviceProvider;

 public BusinessLocation() {  
 }

 @Id
 @GeneratedValue
 public Long getId() {
  return id;
 }
 public void setId(Long id) {
  this.id = id;
 }
 public String getAddress() {
  return address;
 }
 public void setAddress(String address) {
  this.address = address;
 }
 public String getCity() {
  return city;
 }
 public void setCity(String city) {
  this.city = city;
 }

 @ManyToOne
 @JoinColumn(name="state_id")
 public State getState() {
  return state;
 }
 public void setState(State state) {
  this.state = state;
 } 
 public void setPincode(String pincode) {
  this.pincode = pincode;
 }

 public String getPincode() {
  return pincode;
 }

 @ManyToOne
 @JoinColumn(name="serviceProvider_id")
 public ServiceProvider getServiceProvider() {
  return serviceProvider;
 }
 public void setServiceProvider(ServiceProvider serviceProvider) {
  this.serviceProvider = serviceProvider;
 }
}

State.java

@Entity
public class State implements Serializable {

 private Long id;
 private String name;
 private List<BusinessLocation> businessLocations;

 @Id
 @GeneratedValue 
 public Long getId() {
  return id;
 }
 public void setId(Long id) {
  this.id = id;
 }
 public void setName(String name) {
  this.name = name;
 }

 public String getName() {
  return name;
 }


 @OneToMany(mappedBy="state", targetEntity=BusinessLocation.class, cascade=CascadeType.ALL, fetch=FetchType.EAGER)
 public List<BusinessLocation> getBusinessLocations() {
  return businessLocations;
 }
 public void setBusinessLocations(List<BusinessLocation> businessLocations) {
  this.businessLocations = businessLocations;
 } 

}

期待有人把我弄错，我可能会在这里犯这个错误。 感谢。

Answer 1

感谢您的回复。我认为这个错误正在被创建，因为我无意中试图在我的视图中覆盖由选择标记的路径集中的Hibernate创建的ID。

以下是我的服务和dao类的代码： ServiceProviderServiceImpl

@Transactional
public class ServiceProviderServiceImpl implements ServiceProviderService{

    private ServiceProviderDAO serviceProviderDAO;
    public void setServiceProviderDAO(ServiceProviderDAO serviceProviderDAO) {
        this.serviceProviderDAO = serviceProviderDAO;
    }

    public void addServiceProvider(ServiceProvider serviceProvider) {
        serviceProviderDAO.save(serviceProvider);
        for(BusinessLocation businessLocation: serviceProvider.getBusinessLocations()) {
            businessLocation.setServiceProvider(serviceProvider);
            serviceProviderDAO.save(businessLocation);
        }

    }

}

<强> ServiceProviderDAOImpl     公共类ServiceProviderDAOImpl实现ServiceProviderDAO {

    private HibernateTemplate hibernateTemplate;
    public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
        this.hibernateTemplate = hibernateTemplate;
    }

    public void save(ServiceProvider serviceProvider) {
        hibernateTemplate.saveOrUpdate(serviceProvider);        
    }

    public void save(BusinessLocation businessLocation) {
        hibernateTemplate.saveOrUpdate(businessLocation);       
    }

}

但是一旦我解决了这个问题，我就开始出现以下错误：

org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: com.inception.domain.State; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.inception.domain.State
   at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:634)
   at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412)
   at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:378)
   at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:639)
   at com.inception.dao.ServiceProviderDAOImpl.save(ServiceProviderDAOImpl.java:23)
   at com.inception.service.ServiceProviderServiceImpl.addServiceProvider(ServiceProviderServiceImpl.java:21)
   at com.inception.web.RegisterServiceProviderController.processFinish(RegisterServiceProviderController.java:68)
   at org.springframework.web.servlet.mvc.AbstractWizardFormController.validatePagesAndFinish(AbstractWizardFormController.java:642)
   at org.springframework.web.servlet.mvc.AbstractWizardFormController.processFormSubmission(AbstractWizardFormController.java:492)
   at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:265)
   at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
   at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
   at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
   at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809)
   at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:476)
   at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:441)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
   at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
   at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
   at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
   at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
   at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
   at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
   at java.lang.Thread.run(Thread.java:619)
Caused by: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.inception.domain.State
   at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:219)
   at org.hibernate.type.EntityType.getIdentifier(EntityType.java:397)
   at org.hibernate.type.ManyToOneType.isDirty(ManyToOneType.java:242)
   at org.hibernate.type.TypeFactory.findDirty(TypeFactory.java:596)
   at org.hibernate.persister.entity.AbstractEntityPersister.findDirty(AbstractEntityPersister.java:3128)
   at org.hibernate.event.def.DefaultFlushEntityEventListener.dirtyCheck(DefaultFlushEntityEventListener.java:478)
   at org.hibernate.event.def.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:204)
   at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:127)
   at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:196)
   at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:76)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1004)
   at org.springframework.orm.hibernate3.HibernateAccessor.flushIfNecessary(HibernateAccessor.java:390)
   at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:374)
   ... 27 more

我通过在实体 BusinessLocation.java 中将cascade属性设置为（ cascade = CascadeType.ALL ）来解决问题。

@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="state_id")
public State getState() {
    return state;
}

非常感谢您的回复：）

Answer 2

映射看起来是正确的，显示实际尝试持久化ServiceProvider实例的代码会很有趣。

特别是，我会特别注意各种双向关联，以确保在保持之前正确设置“双方链接”。

您可能真的想为此创建链接管理方法，例如在ServiceProvider：

中

@Entity
public class ServiceProvider implements Serializable{
    private Long id; 
    private Set<BusinessLocation> businessLocations = new HashSet<BusinessLocation>();

    @Id @GeneratedValue
    public Long getId() {
      return id;
    }
    public void setId(Long id) {
      this.id = id;
    }

    @OneToMany(mappedBy="serviceProvider", targetEntity=BusinessLocation.class, cascade=CascadeType.ALL, fetch=FetchType.EAGER)
    public Set<BusinessLocation> getBusinessLocations() {
      return businessLocations;
    }

    public void setBusinessLocations(Set<BusinessLocation> businessLocations) {
      this.businessLocations = businessLocations;
    }

    public void addToBusinessLocations(BusinessLocation businessLocation) {
      this.getBusinessLocations().add(businessLocation);
      businessLocation.setServiceProvider(this);
    }

    public void removeFromBusinessLocations(BusinessLocation businessLocation) {
      this.getBusinessLocations().remove(businessLocation);
      businessLocation.setServiceProvider(null);
    }        
}

State中也是如此。

未正确设置链接的两侧可能是问题的原因。