Hibernate Annotation Error (org.hibernate.exception.SQLGrammarException: could not insert: [com.hib.ex.entity.Node])

Question

I'm a beginner in Hibernate Annotation and I'd like to implement an example but it gives me the following error message :

****************WRITING****************
log4j:WARN No appenders could be found for logger (org.hibernate.type.BasicTypeRegistry).
log4j:WARN Please initialize the log4j system properly.
Hibernate: insert into Node (group, name) values (?, ?)
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not insert: [com.hib.ex.entity.Node]
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
    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:2345)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2852)
    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.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
    at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
    at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:713)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:701)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:697)
    at com.hib.ex.dao.HibExDao.saveNode(HibExDao.java:19)
    at com.hib.ex.main.Run.main(Run.java:18)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'group, name) values (null, 'zakaria')' at line 1
    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:532)
    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:3558)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3490)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2109)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2643)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2077)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2362)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2280)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2265)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
    ... 17 more

This is the entity class Node :

package com.hib.ex.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="Node")
public class Node {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer id;

    @Column
    private String name;

    @Column
    private Integer group;

    public Node() {
        super();
        // TODO Auto-generated constructor stub
    }

    public Node(Integer id, String name, Integer group) {
        super();
        this.id = id;
        this.name = name;
        this.group = group;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public Integer getGroup() {
        return group;
    }

    public void setGroup(Integer group) {
        this.group = group;
    }

}

This is the DAO class HibExDao :

package com.hib.ex.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

import com.hib.ex.entity.HyperEdge;
import com.hib.ex.entity.Node;

public class HibExDao {

    public void saveNode(Node noeud) {

        SessionFactory sf = HibExUtil.getSessionFactory();
        Session session = sf.openSession();
        session.beginTransaction();

        session.save(noeud);

        session.getTransaction().commit();
        session.close();

    }

    public List listNode() {

        SessionFactory sf = HibExUtil.getSessionFactory();
        Session session = sf.openSession();

        List nodes = session.createQuery("FROM Node").list();
        session.close();
        return nodes;

    }

    public Node readNode(Integer id) {

        SessionFactory sf = HibExUtil.getSessionFactory();
        Session session = sf.openSession();

        Node noeud = (Node) session.get(Node.class, id);
        session.close();
        return noeud;

    }

}

This is the hibernate.cfg.xml file :

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>
        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/exhiber</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>

        <property name="connection.pool_size">1</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="current_session_context_class">thread</property>
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
        <property name="show_sql">true</property>
        <property name="hbm2ddl.auto">update</property>


        <mapping class="com.hib.ex.entity.Node" />
        <mapping class="com.hib.ex.entity.HyperEdge" />

    </session-factory>

</hibernate-configuration>

And this is the execution class Run :

package com.hib.ex.main;

import java.util.List;

import com.hib.ex.dao.HibExDao;
import com.hib.ex.entity.Node;

public class Run {


    public static void main(String[] args) {

        HibExDao dao = new HibExDao();

        System.out.println("****************WRITING****************");
        Node n1 = new Node();
        n1.setName("zakaria");
        dao.saveNode(n1);
        System.out.println("Node saved!");
        Node n2 = new Node();
        n2.setName("anas");
        dao.saveNode(n2);
        System.out.println("Node saved!");

        System.out.println("\n****************READING****************");
        List nodes = dao.listNode();
        System.out.println("Name in Node number 2 is: " + dao.readNode(2).getName());

    }

}

What is the problem? And can I solve it?

Thanks!

It says group can't be null. Add a group n1.setGroup(blah) and give it a go — happybuddha, Jul 06 '14 at 22:23
Thanks @happybuddha, I tried, it still gives the same error. — user1885868, Jul 06 '14 at 22:28

score 1 · Accepted Answer · edited May 23 '17 at 12:05

The cause is clearly mentioned:

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'group, name) values (null, 'zakaria')' at line 1

Your entity contains an attribute that contribute to this issue:

@Column
private Integer group;

The answer is simple group is a reserved SQL keyword (see GROUP BY clause`)

To resolve this, you need to rename to column name and map it correctly to your entity attribute.

Also, you are not populating the group field, hence it's NULL. Perhaps MySQL doesn't accept NULL for this column?

I hope this helps.

If you want to use the reserved keyword, you can do it using the following specification:

In JPA 2.0:

@Column(name="\"group\"")

In Hibernate:

@Column(name="'group'")

Reference.

Is there a way to work around that problem? Because I really want that particular name "group" — user1885868, Jul 06 '14 at 22:30

score 0 · Answer 2 · answered Jul 06 '14 at 22:27

0

To work you have to set the group property or allow it to be null ( nullable=true)

answered Jul 06 '14 at 22:27

Pracede

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Thanks @Pracede, I tried, it still gives the same error. – user1885868 Jul 06 '14 at 22:31

Hibernate Annotation Error (org.hibernate.exception.SQLGrammarException: could not insert: [com.hib.ex.entity.Node])

2 Answers2