प्रिय डेवलपर।कॉलम शून्य नहीं हो सकता
मैं आपको एक प्रश्न पूछने जा रहा हूं जो मुझे लगता है कि मेरे लिए हल करना मुश्किल है क्योंकि मुझे जवाब क्यों नहीं है, मेरा क्या मतलब है ?? चलो देखते हैं। जेबॉस दस्तावेज में एसोसिएशन को व्यापक उत्तर नहीं मिला: मुझे विदेशी कुंजी की बजाय जॉइनटेबल का उपयोग क्यों करना चाहिए और मैं पूरी तरह से समझ नहीं पा रहा हूं कि मैपिंग कैसे काम करती है, इसका मेरा क्या अर्थ है? मुझे पता है कि एसोसिएशन क्या है कई टोमनी या मनीटोन इत्यादि। और किस उद्देश्य के लिए वे हैं, लेकिन वे एक दूसरे के साथ कैसे काम करते हैं और सहयोग करते हैं को द्वि-दिशात्मक या यूनिडायरेक्शनल या जॉइनटेबल या एसोसिएशन के बारे में कोई जवाब नहीं चाहिए, मैं चाहूंगा लिंक है जहां मुझे अपने दो प्रश्नों के बारे में पूरी जानकारी मिल सकती है:
1) मुझे विदेशी कुंजी की बजाय जॉइनटेबल का उपयोग क्यों करना चाहिए ????
2) इकाई कैसे काम करती है और एक-दूसरे के साथ सहयोग करती है (स्पष्टीकरण के बिना कई टोनी आदि संगठनों और द्विपक्षीय संघीय संघ हैं) ??? Name_INSTITUTION और TYPE_NAME (संस्था का प्रकार):: *
मेरे इकाई
तो, मैं कोड का टुकड़ा है, जहां मैं क्योंकि गलतफहमी अटक है, मैं सिर्फ डेटा डालने के लिए मैं MySQL डाटाबेस हूँ कोशिश कर रहा हूँ वर्ग:
@Entity @Table(name="INSTITUTION") public class Institution implements Serializable{ private static final long serialVersionUID = -7636394097858726922L; private int Id; @Id @GeneratedValue(strategy=IDENTITY) @Column(name="ID") public int getId() { return Id; } public void setId(int id) { Id = id; } private int Version; @javax.persistence.Version @Column(name="VERSION") public int getVersion() { return Version; } public void setVersion(int version) { Version = version; } private String Name_Institution; @Column(name="NAME_INSTITUTION") public String getName_Institution() { return Name_Institution; } public void setName_Institution(String name_Institution) { Name_Institution = name_Institution; } private Type type_inInstitution; @ManyToOne @Cascade(org.hibernate.annotations.CascadeType.ALL) @JoinTable(name="TYPE_INSTITUTION", [email protected](name="INSTITUTION_ID"), [email protected](name="TYPE_ID")) public Type getType_inInstitution() { return type_inInstitution; } public void setType_inInstitution(Type type_inInstitution) { this.type_inInstitution = type_inInstitution; }}
मेरी दूसरी इकाई वर्ग:
@Entity @Table(name="TYPE") public class Type implements Serializable { private static final long serialVersionUID = -4246217431412815552L; private String type; public Type(){} public Type(String type) { this.type = type; } private int Type_Id; @Id @GeneratedValue(strategy=IDENTITY) @Column(name="ID") public int getType_Id() { return Type_Id; } public void setType_Id(int type_Id) { Type_Id = type_Id; } private String Type_Name; @Column(name="TYPE_NAME") public String getType_Name() { return Type_Name; } public void setType_Name(String type_Name) { Type_Name = type_Name; } private int Version; @Version @Column(name="VERSION") public int getVersion() { return Version; } public void setVersion(int version) { Version = version; } private Set<Institution> set_Institution_inType = new HashSet<Institution>(); @OneToMany @JoinTable(name="TYPE_INSTITUTION", [email protected](name="TYPE_ID"), [email protected](name="INSTITUTION_ID")) public Set<Institution> getSet_Institution_inType() { return set_Institution_inType; } public void setSet_Institution_inType(Set<Institution> set_Institution_inType) { this.set_Institution_inType = set_Institution_inType; } public void addType(Institution institution) { institution.setType_inInstitution(this); getSet_Institution_inType().add(institution); }}
डीएओ कक्षा:
@Repository("daoInsertDataInterface") @Transactional public class InsertDataService implements DaoInsertDataInterface{ private org.apache.commons.logging.Log log= LogFactory.getLog(InsertDataService.class); private SessionFactory sessionFactory; public SessionFactory getSessionFactory() { return sessionFactory; } @Resource(name="sessionFactory") public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } @Override public Institution insertData(Institution institution) { sessionFactory.getCurrentSession().saveOrUpdate(institution); log.info(institution.getId()); return institution; }}
मेरे metada config:
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"><value>${jdbc.driverClassName}</value></property> <property name="url"><value>${jdbc.connectionValues}</value></property> <property name="username"><value>${jdbc.userName}</value></property> <property name="password"><value>${jdbc.password}</value></property> </bean> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref ="sessionFactory"/> </bean> <context:property-placeholder location="connection.properties"/> <tx:annotation-driven transaction-manager="transactionManager"/> <context:component-scan base-package="edu.demidov.dom, edu.demidov.dao" /> <context:annotation-config /> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref ="dataSource"/> <property name="packagesToScan" value="edu.demidov.dom"/> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop> <prop key="hibernate.max_fetch_depth">3</prop> <prop key="hibernate.jdbc.fetch_size">50</prop> <prop key="hibernate.jdbc.batch_size">10</prop> <prop key="hibernate.show_sql">true</prop> </props> </property> </bean>,210
और त्रुटि:
INFO : org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [app-context.xml] INFO : org.springframework.context.annotation.ClassPathBeanDefinitionScanner - JSR-330 'javax.inject.Named' annotation found and supported for component scanning INFO : org.springframework.context.support.GenericXmlApplicationContext - Refreshing o[email protected]c93274: startup date [Thu May 09 11:38:23 EDT 2013]; root of context hierarchy INFO : org.springframework.beans.factory.config.PropertyPlaceholderConfigurer - Loading properties file from class path resource [connection.properties] INFO : org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor - JSR-330 'javax.inject.Inject' annotation found and supported for autowiring INFO : org.springframework.beans.factory.support.DefaultListableBeanFactory - Pre-instantiating singletons in org.s[email protected]1b9c2f0: defining beans [dataSource,transactionManager,org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,daoInsertDataInterface,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,sessionFactory,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor];
root of factory hierarchy Hibernate: insert into TYPE (TYPE_NAME, VERSION) values (?, ?) WARN : org.hibernate.util.JDBCExceptionReporter - SQL Error: 1048, SQLState: 23000 ERROR: org.hibernate.util.JDBCExceptionReporter - Column 'TYPE_NAME' cannot be null Exception in thread "main" org.hibernate.exception.ConstraintViolationException: could not insert: [edu.demidov.dom.Type] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:96) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2327) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2834) at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273) at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320) at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203) at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:117) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93) at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:685) at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:677) at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:252) at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:392) at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:335) at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:204) at org.hibernate.engine.Cascade.cascade(Cascade.java:161) at org.hibernate.event.def.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:450) at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:282) at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203) at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:117) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93) at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:685) at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:677) at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:673) at edu.demidov.dao.InsertDataService.insertData(InsertDataService.java:32) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) at $Proxy22.insertData(Unknown Source) at edu.demidov.dao.AppTEst.main(AppTEst.java:22) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'TYPE_NAME' cannot be null at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:525) at com.mysql.jdbc.Util.handleNewInstance(Util.java:411) at com.mysql.jdbc.Util.getInstance(Util.java:386) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1041) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4120) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4052) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2503) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2664) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2815) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2458) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2375) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2359) at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94) at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57) ... 44 more SS
धन्यवाद, दोस्तों।
+1। – Jops