错误：'字段列表'中的未知列'this_.idHardDrives' [英] ERROR: Unknown column 'this_.idHardDrives' in 'field list'

问题描述

请在'字段列表'中提供错误：未知列'this_.idHardDrives'。
无法理解数据库中存在的'idHardDrives'字段。

HardDrives.java

 包main.java.table; 
 
 
 import javax.persistence。*; 
 
 @Entity 
 @Table（name =hardDrives）
 public class HardDrives {
 
 @Id @GeneratedValue 
 @Column（ name =idHardDrives）
 private int idHardDrives; 
 @Column（name =name）
 private String nameHardDrives; 
 @Column（name =capacity）
 private int capacity; 
 @Column（name =interface）
 private String interFace; 
 @Column（name =connectionType）
 private String connectionType; 
 @ManyToOne 
 @JoinColumn（name =idBrand）
私人品牌品牌; 
 
 
 
 
 public int getIdHardDrives（）{
 return idHardDrives; 
} 
 
 public void setIdHardDrives（int idHardDrives）{
 this.idHardDrives = idHardDrives; 
} 
 
 public String getNameHardDrives（）{
 return nameHardDrives; 
} 
 
 public void setNameHardDrives（String name）{
 this.nameHardDrives = name; 
} 
 
 public int getCapacity（）{
 return capacity; 
} 
 
 public void setCapacity（int capacity）{
 this.capacity = capacity; 
} 
 
 public String getInterFace（）{
 return interFace; 
} 
 
 public void setInterFace（String interFace）{
 this.interFace = interFace; 
} 
 
 public String getConnectionType（）{
 return connectionType; 
} 
 
 public void setConnectionType（String connectionType）{
 this.connectionType = connectionType; 
} 
 
 public void setBrand（品牌品牌）{
 this.brands =品牌; 
} 
 
公共品牌getBrands（）{
返回品牌; 
} 
} 
  

Brands.java
package main.java.table;

  import java.util.List; 
 import java.util.Set; 
 
 import javax.persistence。*; 
 
 @Entity 
 @Table（name =Brands）
 public class Brands {
 @Id @GeneratedValue 
 @Column（name =idBrand ）
 private int idBrand; 
 @Column（name =nameBrand）
 private String nameBrand; 
 @OneToMany（mappedBy =品牌）
私人列表< HardDrives> hardDrivesList; 
 
 public Brands（）{} 
 public Brands（int idbr，String namebr）{
 this.idBrand = idbr; 
 this.nameBrand = namebr; 
} 
 
 public int getIdBrand（）{
 return idBrand; 
} 
 
 public void setIdBrand（int id）{
 this.idBrand = id; 
} 
 
 public String getNameBrand（）{
 return nameBrand; 
} 
 
 public void setNameBrand（String name）{
 this.nameBrand = name; 
} 
 
 
公开列表< HardDrives> getHardDrives（）{
 return hardDrivesList; 
} 
 
 public void setHardDrives（List< HardDrives> hardDrives）{
 this.hardDrivesList = hardDrives; 
} 
 
} 
  

HardDrivesDaoImpl.java

  package main.java.dao.impl; 
 
 import java.sql.SQLException; 
 import java.util.List; 
 
 import org.hibernate.Session; 
 
 import main.java.dao.HardDrivesDao; 
导入main.java.table.Brands; 
 import main.java.table.HardDrives; 
 import main.java.util.HibernateUtil; 
 
 public class HardDrivesDaoImpl implements HardDrivesDao {
 $ b $ @Override 
 public void addHardDrive（HardDrive hardDrive）throws SQLException {
 Session session = null; 
 try {
 session = HibernateUtil.getSessionFactory（）。openSession（）; 
 session.beginTransaction（）; 
 session.save（hardDrive）; 
 session.getTransaction（）。commit（）; 
} catch（Exception e）{
 e.printStackTrace（）; $（
）finally {
 if（（session！= null）&&（session.isOpen（）））
 session.close（）; 
 
 
 
 
 $覆盖
 public void deleteHardDrive（HardDrive硬盘驱动器）抛出SQLException {
 Session session = null ; 
 try {
 session = HibernateUtil.getSessionFactory（）。openSession（）; 
 session.beginTransaction（）; 
 session.delete（hardDrive）; 
 session.getTransaction（）。commit（）; 
} catch（Exception e）{
 e.printStackTrace（）; $（
）finally {
 if（（session！= null）&&（session.isOpen（）））
 session.close（）; 
} 
 $ b} 
 
 @Override 
 public HardDrives getHardDrive（int id）抛出SQLException {
 HardDrives result = null; 
会话会话=空; 
 try {
 session = HibernateUtil.getSessionFactory（）。openSession（）; 
 result =（HardDrives）session.load（HardDrives.class，id）; 
} catch（Exception e）{
 e.printStackTrace（）; $（
）finally {
 if（（session！= null）&&（session.isOpen（）））
 session.close（）; 
} 
返回结果; 
} 
 
 @覆盖
公开列表< HardDrives> getHardDrives（）抛出SQLException {
 List< HardDrives> hardDrives = null; 
 
会话会话=空; 
 try {
 session = HibernateUtil.getSessionFactory（）。openSession（）; 
 hardDrives = session.createCriteria（HardDrives.class）.list（）; 
返回null; 
} catch（Exception e）{
 e.printStackTrace（）; $（
）finally {
 if（（session！= null）&&（session.isOpen（）））
 session.close（）; 
} 
返回hardDrives; 
} 
 
} 
  

Main.java

  package main.java.general; 
 
 import java.sql.SQLException; 
 import java.util.Iterator; 
 import java.util.List; 
 
 import main.java.dao.impl.HardDrivesDaoImpl; 
导入main.java.table.Brands; 
 import main.java.table.HardDrives; 
 import main.java.util.HibernateUtil; 
 
 import org.hibernate.HibernateException; 
 import org.hibernate.Session; 
 import org.hibernate.SessionFactory; 
 import org.hibernate.Transaction; 
 
 
 public class Main {
 
 
 public static void main（String [] args）throws SQLException {
 
 HardDrivesDaoImpl hardDrives = new HardDrivesDaoImpl（）; 
 List< HardDrives> hardDrivesList = hardDrives.getHardDrives（）; 
（HardDrives hd：hardDrivesList）{
 System.out.print（Id：+ hd.getIdHardDrives（））; 
 System.out.print（Name：+ hd.getNameHardDrives（））; 
 System.out.println（Capacity：+ hd.getCapacity（））; 
 System.out.println（Interface：+ hd.getInterFace（））; 
 System.out.println（Connection Type：+ hd.getConnectionType（））; 
 System.out.println（Brand：+ hd.getBrands（））; 
 
 System.out.println（\\\
）; 
} 
 
} 
} 
  

错误

 фев13，2015 4:57:58 PM org.hibernate.annotations.common.reflection。 java.JavaReflectionManager< clinit> 
 INFO：HCANN000001：Hibernate Commons Annotations {4.0.5.Final} 
 2015年7月13日下午4时57分58秒org.hibernate.Version logVersion 
 INFO：HHH000412：Hibernate Core {4.3 .7.Final} 
фев13，2015 4:57:58 PM org.hibernate.cfg.Environment< clinit> 
 INFO：HHH000206：找不到hibernate.properties 
 2015年7月13日下午4时57分58秒org.hibernate.cfg.Environment buildBytecodeProvider 
 INFO：HHH000021：字节码提供程序名称：javassist 
фев13，2015 4:57:58 PM org.hibernate.cfg.Configuration configure 
 INFO：HHH000043：从资源配置：/hibernate.cfg.xml 
фев13，2015 4:57： 58下午org.hibernate.cfg.Configuration getConfigurationInputStream 
 INFO：HHH000040：配置资源：/hibernate.cfg.xml 
 2015年7月13日下午4时57分58秒org.hibernate.cfg.Configuration doConfigure 
 INFO：HHH000041：配置SessionFactory：null 
 2015年7月13日下午4时57分58秒org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl配置
警告：HHH000402：使用Hibernate内置-in连接池（不适用于生产使用！）
фев13，2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator 
 INFO：HHH000401：using driver [com.mysql.jdbc.Driver] at URL [jdbc：mysql：// localhost / storage] 
 2015年7月13日下午4时57分58秒org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator 
 INFO：HHH000046：连接属性：{user = root，password = ****} 
 2015年7月13日下午4时57分58秒org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator 
 INFO：HHH000006：Autocommit模式：false 
 2015年7月13日下午4时57分58秒org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl配置
 INFO：HHH000115：Hibernate连接池大小：20（min = 1）
фев13，2015 4:57:59 PM org.hibernate.dialect.Dialect< init> 
 INFO：HHH000400：使用方言：org.hibernate.dialect.MySQLDialect 
фев13，2015 4:57:59 PM org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation 
 INFO： HHH000423：禁用根据JDBC驱动程序报告的上下文LOB创建JDBC版本[3]小于4 
 2015年7月13日4:57:59 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService 
 INFO： HHH000399：使用默认事务策略（直接JDBC事务）
фев13，2015 4:57:59 PM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory< init> 
 INFO：HHH000397：使用ASTQueryTranslatorFactory 
 2015年7月13日4:57:59 org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions 
 WARN：SQL错误：1054，SQLState：42S22 
фев13，2015 4:57:59 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions 
错误：未知列'this_.idHardDrives'in'field list'
 org。 hibernate.exception.SQLGrammarException：无法从org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert（SQLExceptionTypeDelegate.java:80）中提取ResultSet 
在org.hibernate.exception.internal.StandardSQLExceptionConverter.convert上的
 StandardSQLExceptionConverter.java:49）
 at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert（SqlExceptionHelper.java:126）
 at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert（ SqlExceptionHelper.java:112）
 at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract（ResultSetReturnImpl.java:91）
 at org.hibernate.loader.Loader.getResultSet （Loader.java:2066）
在org.hibernate.loader.Loader.executeQueryStatement（Loader.java:1863）
在org.hibernate.loader.Loader.executeQueryStatement（Loader.java:1839）
在org.hibernate.loader.Loader.doQuery（Loader.java:910）
在org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections（Loader.java:355）
在org.hibernate。 loader.Loader.doList（Loader.java:2554）
在org.hibernate.loader.Loader.doList（Loader.java:2540）
在org.hibernate.loader.Loader.listIgnoreQueryCache（Loader。 java：2370）
在org.hibernate.loader.Loader.list（Loader.java:2365）
在org.hibernate.loader.criteria.CriteriaLoader.list（CriteriaLoader.java:126）
在org.hibernate.internal.SessionImpl.list（SessionImpl.java:1682）
在org.hibernate.internal.CriteriaImpl.list（CriteriaImpl.java:380）
在main.java.dao .impl.HardDrivesDaoImpl.getHardDrives（HardDrivesDaoImpl.java:73）
位于main.java.general.Main.main（Main.java:44）
引起：com.mysql.jdbc.exceptions.jdbc4 .MySQLSynta xErrorException：'字段列表'中未知列'this_.idHardDrives'$ b $ sun.reflect.NativeConstructorAccessorImpl.newInstance0（本地方法）
 sun.reflect.NativeConstructorAccessorImpl.newInstance（未知源）
在sun.reflect.DelegatingConstructorAccessorImpl.newInstance（未知源）
在java.lang.reflect.Constructor.newInstance（未知源）
在com.mysql.jdbc.Util.handleNewInstance（Util.java:406 ）
 at com.mysql.jdbc.Util.getInstance（Util.java:381）
 at com.mysql.jdbc.SQLError.createSQLException（SQLError.java:1030）
 at com。 mysql.jdbc.SQLError.createSQLException（SQLError.java:956）
 at com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3491）
 at com.mysql.jdbc.MysqlIO.checkErrorPacket（ MysqlIO.java:3423）
 at com.mysql.jdbc.MysqlIO.sendCommand（MysqlIO.java:1936）
 at com.mysql.jdbc.MysqlIO.sqlQueryDirect（MysqlIO.java:2060）
 at com.mysql.jdbc.ConnectionImpl.execSQL（ConnectionImpl.java:2542）
 at com.mysql.jdbc.Prepar edStatement.executeInternal（PreparedStatement.java:1734）
 at com.mysql.jdbc.PreparedStatement.executeQuery（PreparedStatement.java:1885）
 at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract（ ResultSetReturnImpl.java:82）
 ... 14 more 
线程main中的异常java.lang.NullPointerException $ main.java.general.Main.main中的
（Main.java:45 ）
  

解决方案

在桌子里。
MySQL Workbench没有在字段名称中显示空格，我对其进行了更正并完成了所有工作。

Please help with ERROR: Unknown column 'this_.idHardDrives' in 'field list'. Can`t understand the field 'idHardDrives' exist in the database.

HardDrives.java

package main.java.table;


import javax.persistence.*;

@Entity
@Table(name = "hardDrives")
public class HardDrives {

@Id @GeneratedValue
@Column(name = "idHardDrives")
private int idHardDrives;
@Column(name = "name")
private String nameHardDrives;
@Column(name = "capacity")
private int capacity;
@Column(name = "interface")
private String interFace;
@Column(name = "connectionType")
private String connectionType;
@ManyToOne
@JoinColumn (name = "idBrand")
private Brands brands;




public int getIdHardDrives() {
    return idHardDrives;
}

public void setIdHardDrives(int idHardDrives) {
    this.idHardDrives = idHardDrives;
}

public String getNameHardDrives() {
    return nameHardDrives;
}

public void setNameHardDrives(String name) {
    this.nameHardDrives = name;
}

public int getCapacity() {
    return capacity;
}

public void setCapacity(int capacity) {
    this.capacity = capacity;
}

public String getInterFace() {
    return interFace;
}

public void setInterFace(String interFace) {
    this.interFace = interFace;
}

public String getConnectionType() {
        return connectionType;
}

public void setConnectionType(String connectionType) {
        this.connectionType = connectionType;
}

public void setBrand(Brands brands){
    this.brands = brands;
}

public Brands getBrands(){
    return brands;
    }
}

Brands.java package main.java.table;

import java.util.List;
import java.util.Set;

import javax.persistence.*;

@Entity
@Table(name = "Brands")
public class Brands {
@Id @GeneratedValue
@Column(name = "idBrand")
private int idBrand;
@Column(name = "nameBrand")
private String nameBrand;
@OneToMany (mappedBy="brands")
private List <HardDrives> hardDrivesList;

public Brands(){}
public Brands(int idbr, String namebr){
    this.idBrand = idbr;
    this.nameBrand = namebr;
}

public int getIdBrand(){
    return idBrand;
}

public void setIdBrand(int id){
    this.idBrand = id;
}

public String getNameBrand(){
    return nameBrand;
}

public void setNameBrand(String name){
    this.nameBrand = name;
}


public List<HardDrives> getHardDrives(){
    return hardDrivesList;
}

    public void setHardDrives(List<HardDrives> hardDrives){
        this.hardDrivesList = hardDrives;
    }

}

HardDrivesDaoImpl.java

package main.java.dao.impl;

import java.sql.SQLException;
import java.util.List;

import org.hibernate.Session;

import main.java.dao.HardDrivesDao;
import main.java.table.Brands;
import main.java.table.HardDrives;
import main.java.util.HibernateUtil;

public class HardDrivesDaoImpl implements HardDrivesDao {

    @Override
    public void addHardDrive(HardDrives hardDrive) throws SQLException {
        Session session = null;
        try{
        session = HibernateUtil.getSessionFactory().openSession();
        session.beginTransaction();
        session.save(hardDrive);
        session.getTransaction().commit();
    } catch(Exception e){
        e.printStackTrace();
    } finally {
        if ((session != null) && (session.isOpen()))
        session.close();
    }


}

@Override
public void deleteHardDrive(HardDrives hardDrive) throws SQLException {
    Session session = null;
    try{
        session = HibernateUtil.getSessionFactory().openSession();
        session.beginTransaction();
        session.delete(hardDrive);
        session.getTransaction().commit();
    } catch(Exception e){
        e.printStackTrace();
    } finally {
        if ((session != null) && (session.isOpen()))
        session.close();
    }

}

@Override
public HardDrives getHardDrive(int id) throws SQLException {
    HardDrives result = null;
    Session session = null;
    try{
        session = HibernateUtil.getSessionFactory().openSession();
        result = (HardDrives)session.load(HardDrives.class, id);
    } catch(Exception e){
        e.printStackTrace();
    } finally {
        if ((session != null) && (session.isOpen()))
        session.close();
    }
    return result;
}

@Override
public List<HardDrives> getHardDrives() throws SQLException {
    List <HardDrives> hardDrives = null;

    Session session = null;
    try{
        session = HibernateUtil.getSessionFactory().openSession();
        hardDrives = session.createCriteria(HardDrives.class).list();
        return null;
        } catch(Exception e){
            e.printStackTrace();
        } finally {
            if ((session != null) && (session.isOpen()))
            session.close();
        }
            return hardDrives;
    }

}

Main.java

package main.java.general;

import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;

import main.java.dao.impl.HardDrivesDaoImpl;
import main.java.table.Brands;
import main.java.table.HardDrives;
import main.java.util.HibernateUtil;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;


public class Main {


public static void main(String[] args) throws SQLException {

    HardDrivesDaoImpl hardDrives = new HardDrivesDaoImpl();
    List<HardDrives>hardDrivesList = hardDrives.getHardDrives();
    for(HardDrives hd :hardDrivesList){
        System.out.print("Id: " + hd.getIdHardDrives()); 
        System.out.print("Name: " + hd.getNameHardDrives()); 
        System.out.println("Capacity: " + hd.getCapacity());
        System.out.println("Interface: " + hd.getInterFace());
        System.out.println("Connection Type: " + hd.getConnectionType());
        System.out.println("Brand: " + hd.getBrands());

        System.out.println("\n");
    }

    }
}

Error

фев 13, 2015 4:57:58 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.5.Final}
фев 13, 2015 4:57:58 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.7.Final}
фев 13, 2015 4:57:58 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
фев 13, 2015 4:57:58 PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
фев 13, 2015 4:57:58 PM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
фев 13, 2015 4:57:58 PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
фев 13, 2015 4:57:58 PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
фев 13, 2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
фев 13, 2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost/storage]
фев 13, 2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000046: Connection properties: {user=root, password=****}
фев 13, 2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000006: Autocommit mode: false
фев 13, 2015 4:57:58 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
фев 13, 2015 4:57:59 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
фев 13, 2015 4:57:59 PM org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
фев 13, 2015 4:57:59 PM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
фев 13, 2015 4:57:59 PM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
фев 13, 2015 4:57:59 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 1054, SQLState: 42S22
фев 13, 2015 4:57:59 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: Unknown column 'this_.idHardDrives' in 'field list'
org.hibernate.exception.SQLGrammarException: could not extract ResultSet
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:80)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:126)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:112)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:91)
at org.hibernate.loader.Loader.getResultSet(Loader.java:2066)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1863)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1839)
at org.hibernate.loader.Loader.doQuery(Loader.java:910)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:355)
at org.hibernate.loader.Loader.doList(Loader.java:2554)
at org.hibernate.loader.Loader.doList(Loader.java:2540)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2370)
at org.hibernate.loader.Loader.list(Loader.java:2365)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:126)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1682)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:380)
at main.java.dao.impl.HardDrivesDaoImpl.getHardDrives(HardDrivesDaoImpl.java:73)
at main.java.general.Main.main(Main.java:44)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'this_.idHardDrives' in 'field list'
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:406)
at com.mysql.jdbc.Util.getInstance(Util.java:381)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1885)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:82)
... 14 more
Exception in thread "main" java.lang.NullPointerException
at main.java.general.Main.main(Main.java:45)

解决方案

It was a problem with name fields in classes and in tables. MySQL Workbench didn't show the space in the field`s name, i corrected it and all work.

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