我正在使用Hibernate将对象保存在数据库中。我正在使用@GeneratedValue注释生成主键。
这是我的代码供应商类
package com.samples.vendor; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; import javax.persistence.Transient; @Entity @Table(name = "Vendor") public class Vendor implements Serializable { /** * */ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY) @Column(name="vendor_ID", unique = true, nullable = false) private int vendor_ID; private String vname; private long phone_no; private String emailID; @Transient private int updated; public int getVendor_ID() { return vendor_ID; } public void setVendor_ID(int vendor_ID) { this.vendor_ID = vendor_ID; } public String getVname() { return vname; } public void setVname(String vname) { this.vname = vname; } public long getPhone_no() { return phone_no; } public void setPhone_no(long phone_no) { this.phone_no = phone_no; } public String getEmailID() { return emailID; } public void setEmailID(String emailID) { this.emailID = emailID; } public int getUpdated() { return updated; } public void setUpdated(int updated) { this.updated = updated; } }
我正在使用MS SQL Server 2012，其中有带有以下列的供应商表
vendor_ID int Unchecked -------> Primary key vname varchar(50) Checked phone_no bigint Checked emailID varchar(50) Checked updated bit Checked
未选中表示其NOTNULL = true，不允许使用空值。
这是我试图将数据保存到数据库中的代码。
@RequestMapping(value = "addVendor", method = RequestMethod.POST) public ModelAndView addVendor(@ModelAttribute("vendor") Vendor vendor, BindingResult result) { if(result.hasErrors()) { ModelAndView modelErr = new ModelAndView("AddVendor"); return modelErr; } Session session = null; try { SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session = sessionFactory.openSession(); session.beginTransaction(); session.save(vendor); session.getTransaction().commit(); ModelAndView modelview = new ModelAndView("Insert"); return modelview; } catch(Exception ex) { ex.printStackTrace(); } finally { session.close(); } return null;
运行此命令时，出现以下错误
Hibernate: insert into Vendor (emailID, phone_no, vname) values (?, ?, ?) Sep 12, 2015 7:45:53 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions WARN: SQL Error: 515, SQLState: 23000 Sep 12, 2015 7:45:53 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions ERROR: Cannot insert the value NULL into column 'vendor_ID', table 'VendorCalls.dbo.Vendor'; column does not allow nulls. INSERT fails. org.hibernate.exception.ConstraintViolationException: could not execute statement at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:112) at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109) at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:95) at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:207) at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:84) at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:42) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2730) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3300) at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81) at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:474) at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:179) at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:163) at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:198) at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:317) at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:272) at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:178) at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:109) at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192) at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38) at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177) at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32) at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73) at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:678) at org.hibernate.internal.SessionImpl.save(SessionImpl.java:670) at org.hibernate.internal.SessionImpl.save(SessionImpl.java:665) at com.samples.vendor.InsertDB.addVendor(InsertDB.java:39) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) at javax.servlet.http.HttpServlet.service(HttpServlet.java:650) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source) Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: Cannot insert the value NULL into column 'vendor_ID', table 'VendorCalls.dbo.Vendor'; column does not allow nulls. INSERT fails. at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:216) at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServerStatement.java:1515) at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:404) at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(SQLServerPreparedStatement.java:350) at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:5696) at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:1715) at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLServerStatement.java:180) at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLServerStatement.java:155) at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(SQLServerPreparedStatement.java:314) at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:204) ... 59 more
请帮我解决一下这个。我是新来的hibernate并试图学习它。先感谢您。
如果对@GeneratedValue使用策略javax.persistence.GenerationType.IDENTITY，则表必须具有标识生成器。这可以通过在主键中包含AUTO_INCREMENT来完成。
示例：CREATE TABLE供应商（ID int NOT NULL AUTO_INCREMENT，PRIMARY KEY（ID））
