休眠的奇怪行为

Question

我是hibernate的新手，我从中获得了一些奇怪的行为，下面就是这个场景。

我的java文件是

UserDetails.java

package org.javabrains.faisal.dto;
import java.util.ArrayList;
import java.util.Collection;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
@Entity
@Table(name = "USER_DETAILS")
public class UserDetails {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "USER_ID")
    private int userId;

    @Column(name = "USER_NAME")
    private String userName;

    @ManyToMany
    @JoinTable(name="USER_VEHICLE",joinColumns=@JoinColumn(name="USER_ID"),inverseJoinColumns=@JoinColumn(name="VEHICLE_ID"))
    private Collection<Vehicle> vehicle = new ArrayList<>();

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Collection<Vehicle> getVehicle() {
        return vehicle;
    }

    public void setVehicle(Collection<Vehicle> vehicle) {
        this.vehicle = vehicle;
    }

}

Vehicle.java

package org.javabrains.faisal.dto;
import java.util.ArrayList;
import java.util.Collection;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
@Entity
@Table(name="VEHICLE")
public class Vehicle {
    @Id
    @GeneratedValue
    @Column(name="VEHICLE_ID")
    private int vehicleId;

    @Column(name="VEHICLE_NAME")
    private String vehicleName;

    @ManyToMany(mappedBy="vehicle")
    private Collection<UserDetails> userList=new ArrayList<UserDetails>();


    public Collection<UserDetails> getUserList() {
        return userList;
    }

    public void setUserList(Collection<UserDetails> userList) {
        this.userList = userList;
    }

    public int getVehicleId() {
        return vehicleId;
    }

    public void setVehicleId(int vehicleId) {
        this.vehicleId = vehicleId;
    }

    public String getVehicleName() {
        return vehicleName;
    }

    public void setVehicleName(String vehicleName) {
        this.vehicleName = vehicleName;
    }


}

HibernateTest.java

package org.javabrain.faisal.hibernate;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.javabrains.faisal.dto.UserDetails;
import org.javabrains.faisal.dto.Vehicle;
public class HibernateTest {

    public static void main(String[] args) {
        UserDetails user = new UserDetails();
        UserDetails user2 = new UserDetails();
        user.setUserName("Faisal");
        user2.setUserName("Raza");



        Vehicle vehicle=new Vehicle();
        Vehicle vehicle2=new Vehicle();
        Vehicle vehicle3=new Vehicle();

        vehicle.setVehicleName("Bullet ThunderBird");
        vehicle2.setVehicleName("yamaha");
        vehicle3.setVehicleName("bullet");


        //Didirectional relationship
        user.getVehicle().add(vehicle);
        vehicle.getUserList().add(user);

        user.getVehicle().add(vehicle2);
        vehicle2.getUserList().add(user);

        user2.getVehicle().add(vehicle3);
        vehicle3.getUserList().add(user2);

        // sessionFactory one object per application
        SessionFactory sessionFactory = new Configuration().configure()
                .buildSessionFactory();
        Session session = sessionFactory.openSession();

        session.beginTransaction(); 
        session.save(user);
        session.save(user2);

        session.save(vehicle);
        session.save(vehicle2);
        session.save(vehicle3);
        session.getTransaction().commit();
        session.close();



    }

}

hibernate.cfg.xml文件

<?xml version='1.0' encoding='utf-8'?>
<!--
  ~ Hibernate, Relational Persistence for Idiomatic Java
  ~
  ~ License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  ~ See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  -->
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <!-- 3306 is default port number for mysql -->
        <property name="connection.url">jdbc:mysql://localhost:3306/hibernatedb</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- re-create the database every time -->
        <property name="hbm2ddl.auto">create</property>

        <!-- Name the annotated entity class 
        Here we have declared the class which have entities

        if you define a new entity class; an entry goes here below
        -->
        <mapping class="org.javabrains.faisal.dto.UserDetails"/>
        <mapping class="org.javabrains.faisal.dto.Vehicle"/>

    </session-factory>

</hibernate-configuration>

我在userDetails.java

中添加了以下代码

@JoinTable(name="USER_VEHICLE",joinColumns=@JoinColumn(name="USER_ID"),inverseJoinColumns=@JoinColumn(name="VEHICLE_ID"))

并运行应用程序： -

完整的堆栈跟踪，同时在数据库中运行了先前应用程序运行的表（没有上面一行）...

Feb 26, 2016 12:58:13 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.1.0.Final}
Feb 26, 2016 12:58:13 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Feb 26, 2016 12:58:13 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Feb 26, 2016 12:58:13 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Feb 26, 2016 12:58:13 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Feb 26, 2016 12:58:13 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernatedb]
Feb 26, 2016 12:58:13 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, password=****}
Feb 26, 2016 12:58:13 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Feb 26, 2016 12:58:13 AM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Feb 26, 2016 12:58:14 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Hibernate: alter table USER_VEHICLE drop foreign key FK48dbrk0k7004g3jff5xftyrxx
Hibernate: alter table USER_VEHICLE drop foreign key FKay5vn6ovfwhmoi2w1wrxxry0
Hibernate: drop table if exists hibernate_sequence
Hibernate: drop table if exists USER_DETAILS
Feb 26, 2016 12:58:15 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Unable to execute command [drop table if exists USER_DETAILS]
org.hibernate.tool.schema.spi.CommandAcceptanceException: Unable to execute command [drop table if exists USER_DETAILS]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:63)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:370)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:355)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:240)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:153)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:125)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:111)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:137)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:64)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:458)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at org.javabrain.faisal.hibernate.HibernateTest.main(HibernateTest.java:40)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint 
fails
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.Util.getInstance(Util.java:383)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:844)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:748)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:51)
    ... 13 more

Hibernate: drop table if exists USER_VEHICLE
Hibernate: drop table if exists VEHICLE
Feb 26, 2016 12:58:16 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Unable to execute command [drop table if exists VEHICLE]
org.hibernate.tool.schema.spi.CommandAcceptanceException: Unable to execute command [drop table if exists VEHICLE]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:63)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:370)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:355)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:240)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:153)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:125)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:111)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:137)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:64)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:458)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at org.javabrain.faisal.hibernate.HibernateTest.main(HibernateTest.java:40)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint 
fails
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.Util.getInstance(Util.java:383)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:844)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:748)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:51)
    ... 13 more

Hibernate: create table hibernate_sequence (next_val bigint)
Hibernate: insert into hibernate_sequence values ( 1 )
Hibernate: insert into hibernate_sequence values ( 1 )
Hibernate: create table USER_DETAILS (USER_ID integer not null, USER_NAME varchar(255), primary key (USER_ID))
Feb 26, 2016 12:58:16 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Unable to execute command [create table USER_DETAILS (USER_ID integer not null, USER_
NAME varchar(255), primary key (USER_ID))]
org.hibernate.tool.schema.spi.CommandAcceptanceException: Unable to execute command [create table USER_DETAILS (USER_ID integer not null, USER_NAME va
rchar(255), primary key (USER_ID))]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:63)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:423)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:408)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:310)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:165)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:134)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:120)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:148)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:64)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:458)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at org.javabrain.faisal.hibernate.HibernateTest.main(HibernateTest.java:40)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'user_details' already exists
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.Util.getInstance(Util.java:383)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:980)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:844)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:748)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:51)
    ... 13 more

Hibernate: create table USER_VEHICLE (USER_ID integer not null, VEHICLE_ID integer not null)
Hibernate: create table VEHICLE (VEHICLE_ID integer not null, VEHICLE_NAME varchar(255), primary key (VEHICLE_ID))
Feb 26, 2016 12:58:16 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Unable to execute command [create table VEHICLE (VEHICLE_ID integer not null, VEHICLE
_NAME varchar(255), primary key (VEHICLE_ID))]
org.hibernate.tool.schema.spi.CommandAcceptanceException: Unable to execute command [create table VEHICLE (VEHICLE_ID integer not null, VEHICLE_NAME v
archar(255), primary key (VEHICLE_ID))]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:63)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:423)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:408)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:310)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:165)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:134)
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:120)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:148)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:64)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:458)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at org.javabrain.faisal.hibernate.HibernateTest.main(HibernateTest.java:40)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'vehicle' already exists
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.Util.getInstance(Util.java:383)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:980)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:844)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:748)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:51)
    ... 13 more

使用（无代码更改）重新运行应用程序并在stacktrace中没有错误

Feb 26, 2016 1:01:22 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.1.0.Final}
Feb 26, 2016 1:01:22 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Feb 26, 2016 1:01:22 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Feb 26, 2016 1:01:22 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Feb 26, 2016 1:01:22 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Feb 26, 2016 1:01:22 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernatedb]
Feb 26, 2016 1:01:22 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, password=****}
Feb 26, 2016 1:01:22 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Feb 26, 2016 1:01:22 AM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Feb 26, 2016 1:01:23 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Hibernate: alter table USER_VEHICLE drop foreign key FK48dbrk0k7004g3jff5xftyrxx
Hibernate: alter table USER_VEHICLE drop foreign key FKay5vn6ovfwhmoi2w1wrxxry0
Hibernate: drop table if exists hibernate_sequence
Hibernate: drop table if exists USER_DETAILS
Hibernate: drop table if exists USER_VEHICLE
Hibernate: drop table if exists VEHICLE
Hibernate: create table hibernate_sequence (next_val bigint)
Hibernate: insert into hibernate_sequence values ( 1 )
Hibernate: insert into hibernate_sequence values ( 1 )
Hibernate: create table USER_DETAILS (USER_ID integer not null, USER_NAME varchar(255), primary key (USER_ID))
Hibernate: create table USER_VEHICLE (USER_ID integer not null, VEHICLE_ID integer not null)
Hibernate: create table VEHICLE (VEHICLE_ID integer not null, VEHICLE_NAME varchar(255), primary key (VEHICLE_ID))
Hibernate: alter table USER_VEHICLE add constraint FK48dbrk0k7004g3jff5xftyrxx foreign key (VEHICLE_ID) references VEHICLE (VEHICLE_ID)
Hibernate: alter table USER_VEHICLE add constraint FKay5vn6ovfwhmoi2w1wrxxry0 foreign key (USER_ID) references USER_DETAILS (USER_ID)
Feb 26, 2016 1:01:28 AM org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSources
INFO: HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@1ad9bb2'
Hibernate: select next_val as id_val from hibernate_sequence for update
Hibernate: update hibernate_sequence set next_val= ? where next_val=?
Hibernate: select next_val as id_val from hibernate_sequence for update
Hibernate: update hibernate_sequence set next_val= ? where next_val=?
Hibernate: select next_val as id_val from hibernate_sequence for update
Hibernate: update hibernate_sequence set next_val= ? where next_val=?
Hibernate: select next_val as id_val from hibernate_sequence for update
Hibernate: update hibernate_sequence set next_val= ? where next_val=?
Hibernate: select next_val as id_val from hibernate_sequence for update
Hibernate: update hibernate_sequence set next_val= ? where next_val=?
Hibernate: insert into USER_DETAILS (USER_NAME, USER_ID) values (?, ?)
Hibernate: insert into USER_DETAILS (USER_NAME, USER_ID) values (?, ?)
Hibernate: insert into VEHICLE (VEHICLE_NAME, VEHICLE_ID) values (?, ?)
Hibernate: insert into VEHICLE (VEHICLE_NAME, VEHICLE_ID) values (?, ?)
Hibernate: insert into VEHICLE (VEHICLE_NAME, VEHICLE_ID) values (?, ?)
Hibernate: insert into USER_VEHICLE (USER_ID, VEHICLE_ID) values (?, ?)
Hibernate: insert into USER_VEHICLE (USER_ID, VEHICLE_ID) values (?, ?)
Hibernate: insert into USER_VEHICLE (USER_ID, VEHICLE_ID) values (?, ?)

所以我的问题是为什么应用程序在第一次运行中没有成功运行，为什么它在第二次运行中成功运行。

Answer 1

使用

        @ManyToMany(cascade=CascadeType.ALL)
        @JoinTable(name="USER_VEHICLE",joinColumns=@JoinColumn(name="USER_ID"),inverseJoinColumns=@JoinColumn(name="VEHICLE_ID"))
        private Collection<Vehicle> vehicle = new ArrayList<>();

还在hibernate.cfg.xml中删除或修改此属性

<property name="hbm2ddl.auto">update</property>

Answer 2

使用时

  

<property name="hbm2ddl.auto">create</property>

Hibernate首先尝试删除您正在使用的表，然后每次都重新创建它们。

因此，当您第一次运行应用程序时，由于数据库中不存在这些表，您将面临错误。当你下次运行你的程序时，你不会看到上面的错误，因为表存在并且hibernate将能够成功地删除它们。

希望这有帮助。

Answer 3

您遇到的错误是因为您创建/删除表格的顺序：

  

无法删除或更新父行：外键约束   失败

这是因为你在运行时没有删除FK：

drop table if exists USER_DETAILS

您需要更改关系以允许Cascade删除子对象。

这是一个例子：http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-hibspec-cascade

Answer 4

我检查你的映射 - 一切正常，使用相同的Hibernate 5.1版本。看起来问题不在于映射。所以你可以尝试做什么

1. 我使用旧的MySQL版本（4.1）。如果您使用MySQL 5，请尝试设置

   <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>

2. 检查MySQL驱动程序。我使用mysql-connector-java-5.1.37.jar。

3. 使用MySQL删除所有数据库（不是表，而是所有数据库）。

我的try日志中的SQL命令（你可以使用MySQL执行它）

alter table USER_VEHICLE 
    drop 
    foreign key FK48dbrk0k7004g3jff5xftyrxx

alter table USER_VEHICLE 
    drop 
    foreign key FKay5vn6ovfwhmoi2w1wrxxry0

drop table if exists USER_DETAILS

drop table if exists USER_VEHICLE

drop table if exists VEHICLE

create table USER_DETAILS (
    USER_ID integer not null,
    USER_NAME varchar(255),
    primary key (USER_ID)
)

create table USER_VEHICLE (
    USER_ID integer not null,
    VEHICLE_ID integer not null
)

create table VEHICLE (
    VEHICLE_ID integer not null,
    VEHICLE_NAME varchar(255),
    primary key (VEHICLE_ID)
)

alter table USER_VEHICLE 
    add constraint FK48dbrk0k7004g3jff5xftyrxx 
    foreign key (VEHICLE_ID) 
    references VEHICLE (VEHICLE_ID)

alter table USER_VEHICLE 
    add constraint FKay5vn6ovfwhmoi2w1wrxxry0 
    foreign key (USER_ID) 
    references USER_DETAILS (USER_ID)