我正在使用Hibernate来保存数据库中的对象。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,其中我有一个包含以下列的供应商表
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,它不允许空值。
以下是我尝试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;
当我运行此操作时,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
请帮我解决这个问题。我是新手来休眠并试图学习它。提前谢谢。
答案 0 :(得分:3)
如果对@GeneratedValue使用策略javax.persistence.GenerationType.IDENTITY,则表必须具有标识生成器。这可以完成,包括主键的AUTO_INCREMENT。
实施例: CREATE TABLE供应商 ( ID int NOT NULL AUTO_INCREMENT, 主要钥匙(ID) )
答案 1 :(得分:1)
您的vendor_ID
没有默认值,但它有NOT NULL
约束。当您执行INSERT
时,您必须设置vendor_ID
,或者如果您不想手动设置它,则应设置AUTO_INCREMENT
属性以为新行生成唯一标识。请记住,如果您没有为您的id字段设置任何值,则它应该是null或默认值(或者如果您设置该属性,它将执行自动增量)。
@GeneratedValue
注释只是告诉Hibernate数据库本身正在生成此值。所以AUTO_INCREMENT
也应该在数据库中定义。
答案 2 :(得分:0)
我不知道Hibernate ORM是否已经更新了很多,但如果您使用@Column()
,目前必须省略装饰器@GeneratedValue
。
所以你的代码将是
@Id
@GeneratedValue
private int vendor_ID;
而不是
@Id
@GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY)
@Column(name="vendor_ID", unique = true, nullable = false)
private int vendor_ID;
希望它有所帮助。