The following exception is very common if you are the beginner for hibernate.
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in
[jar:file:/D:/HIBERNATE/lib/hibernate-annotations-jar-files/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in
[jar:file:/E:/study%20materials/video%20tutorials/JAVA_J2EE_VIDEO_TUTORIALS/hibernate/hibernate-annotations-jar-files/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in
[jar:file:/D:/HIBERNATE/lib/slf4j-simple-1.5.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
log4j:WARN No appenders could be found for logger
(org.hibernate.type.BasicTypeRegistry).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig
for more info.
Exception in thread "main" org.hibernate.hql.ast.QuerySyntaxException:
student is not mapped [from student]
at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:111)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:93)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:327)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3441)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3325)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:733)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:584)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:301)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:244)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:254)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:124)
at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1770)
at kumar.saroj.ReadStudent.main(ReadStudent.java:18)
this is the complete exception hierarchy.
The above QuerySyntaxException is thrown when we are not mapping the table name properly. The first time hibernate users
can be seen this error because you will map the table name directly in the query. That will not work in the hibernate. You will have to
map the class name that is mapped in the Hibernate configuration file. Look into the following example:
public static void main(String[] args)
{
//Create session factory object
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
//getting session object from session factory
Session session = sessionFactory.openSession();
//getting transaction object from session object
session.beginTransaction();
Query query = session.createQuery("from student");
List<Student> students = query.list();
for(Student student : students)
{
System.out.println("Roll Number: "+student.getRollNumber()+", Student Name: "+student.getStudentName()+", Course: "+student.getCourse());
}
session.getTransaction().commit();
sessionFactory.close();
}
The above code give exception mention in above.
Description:
Your query is not a SQL query. It’s a HQL query. It thus should not use table names, but entity class names (from Student instead of from student).
In above code we using following line. Here “student” is not entity name by default entity name is same as class name so we have use “Student” instead of “student” because of HQL is pick entity name not table name(table name is “student”). So please we care about this concern.
Query query = session.createQuery("from student");
If you using the following code then you got successfully running.
public static void main(String[] args)
{
//Create session factory object
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
//getting session object from session factory
Session session = sessionFactory.openSession();
//getting transaction object from session object
session.beginTransaction();
Query query = session.createQuery("from Student");
List<Student> students = query.list();
for(Student student : students)
{
System.out.println("Roll Number: "+student.getRollNumber()+", Student Name: "+student.getStudentName()+", Course: "+student.getCourse());
}
session.getTransaction().commit();
sessionFactory.close();
}
Here the class names is case sensitive.
