Hibernate QuerySyntaxException: Not Mapped

Question

I am developing a REST API with the use of Jersey and Hibernate. Database is MySQL. I have couple of layers in my design, the dao layer, service layer and REST layer. Please check the below code.

NotificationJSONService.java (REST Layer)

@GET
    @Path("/getActiveNotifications")
    @Produces (MediaType.APPLICATION_JSON)
    public List<Notification> getActiveNotifications()
    {
        NotificationService service = new NotificationService();
        List<Notification> notificationsByUser = service.getActiveNotifications();
        return notificationsByUser;
    }

NotificationService.java (Service Layer)

public List<Notification>getActiveNotifications()
    {
        Session session = getSession();
        Transaction transaction = null;
        List<Notification> list = new ArrayList<Notification>();

        try
        {
            transaction = getTransaction(session);
            list = notificationInterface.getActiveNotifications(session);
            transaction.commit();

        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            session.close();

            for (int i = 0; i < list.size(); i++) {
                User user = new User();
                user.setIduser(list.get(i).getUser().getIduser());
                list.get(i).setUser(user);

                Product product = new Product();
                product.setIdproduct(list.get(i).getProduct().getIdproduct());
                list.get(i).setProduct(product);

                NotificationType notificationType = new NotificationType();
                notificationType.setIdnotificationType(list.get(i).getNotificationType().getIdnotificationType());
                list.get(i).setNotificationType(notificationType);
            }
        }

        return list;
    }

NotificationDAOImpl.java (DAO Layer)

@Override
    public List<Notification> getActiveNotifications(Session session) 
    {
        Query query = session.createQuery("from notification where delete_timestamp IS NULL");
        List list = query.list();
        return list;
    }

As you can see, all the above code is related to a table called as notification. Below is the notification bean information.

Notification.java

public class Notification  implements java.io.Serializable {


     private Integer idnotification;
     private NotificationType notificationType;
     private Product product;
     private User user;
     private Date deleteTimestamp;
     private Date dateCreated;
     private Date lastUpdated;

    public Notification() {
    }

    public Integer getIdnotification() {
        return this.idnotification;
    }

    public void setIdnotification(Integer idnotification) {
        this.idnotification = idnotification;
    }
    public NotificationType getNotificationType() {
        return this.notificationType;
    }

    public void setNotificationType(NotificationType notificationType) {
        this.notificationType = notificationType;
    }
    public Product getProduct() {
        return this.product;
    }

    public void setProduct(Product product) {
        this.product = product;
    }
    public User getUser() {
        return this.user;
    }

    public void setUser(User user) {
        this.user = user;
    }
    public Date getDeleteTimestamp() {
        return this.deleteTimestamp;
    }

    public void setDeleteTimestamp(Date deleteTimestamp) {
        this.deleteTimestamp = deleteTimestamp;
    }
    public Date getDateCreated() {
        return this.dateCreated;
    }

    public void setDateCreated(Date dateCreated) {
        this.dateCreated = dateCreated;
    }
    public Date getLastUpdated() {
        return this.lastUpdated;
    }

    public void setLastUpdated(Date lastUpdated) {
        this.lastUpdated = lastUpdated;
    }
}

Notification.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- Generated Jan 31, 2019, 6:16:44 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
    <class name="xxx.xxx.api.beans.Notification" table="notification" catalog="xxx" optimistic-lock="version">
        <id name="idnotification" type="java.lang.Integer">
            <column name="idnotification" />
            <generator class="identity" />
        </id>
        <many-to-one name="notificationType" class="xxx.xxx.api.beans.NotificationType" fetch="select">
            <column name="notification_type_idnotification_type" not-null="true" />
        </many-to-one>
        <many-to-one name="product" class="xxx.xxx.api.beans.Product" fetch="select">
            <column name="product_idproduct" not-null="true" />
        </many-to-one>
        <many-to-one name="user" class="xxx.xxx.api.beans.User" fetch="select">
            <column name="user_iduser" not-null="true" />
        </many-to-one>
        <property name="deleteTimestamp" type="timestamp">
            <column name="delete_timestamp" length="19" />
        </property>
        <property name="dateCreated" type="timestamp">
            <column name="date_created" length="19" />
        </property>
        <property name="lastUpdated" type="timestamp">
            <column name="last_updated" length="19" not-null="true" />
        </property>
    </class>
</hibernate-mapping>

Below is the notification SQL Table

CREATE TABLE IF NOT EXISTS `notification` (
  `idnotification` INT NOT NULL AUTO_INCREMENT,
  `user_iduser` INT NOT NULL,
  `product_idproduct` INT NOT NULL,
  `notification_type_idnotification_type` INT NOT NULL,
  `delete_timestamp` TIMESTAMP NULL,
  `date_created` TIMESTAMP NULL,
  `last_updated` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`idnotification`),
  INDEX `fk_notification_user1_idx` (`user_iduser` ASC),
  INDEX `fk_notification_product1_idx` (`product_idproduct` ASC),
  INDEX `fk_notification_notification_type1_idx` (`notification_type_idnotification_type` ASC),
  CONSTRAINT `fk_notification_user1`
    FOREIGN KEY (`user_iduser`)
    REFERENCES `user` (`iduser`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_notification_product1`
    FOREIGN KEY (`product_idproduct`)
    REFERENCES `product` (`idproduct`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_notification_notification_type1`
    FOREIGN KEY (`notification_type_idnotification_type`)
    REFERENCES `notification_type` (`idnotification_type`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)

When I run the getActiveNotifications method via the following URL (http://localhost:8080/XXX/rest/notification/getActiveNotifications) I get the below error.

org.hibernate.hql.internal.ast.QuerySyntaxException: notification is not mapped [from notification where delete_timestamp IS NULL]
    at org.hibernate.hql.internal.ast.QuerySyntaxException.generateQueryException(QuerySyntaxException.java:96)
    at org.hibernate.QueryException.wrapWithQueryString(QueryException.java:120)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:234)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:158)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:126)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:88)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:190)
    at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:301)
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:236)
    at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1796)
    at xxx.xxx.api.dao.notification.NotificationDAOImpl.getActiveNotifications(NotificationDAOImpl.java:101)
    at xxx.xxx.api.service.NotificationService.getActiveNotifications(NotificationService.java:299)
    at xxx.xxx.api.rest.NotificationJSONService.getActiveNotifications(NotificationJSONService.java:114)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:76)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:148)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:191)
    at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:243)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:103)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:493)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:415)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:104)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:277)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:272)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:268)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:316)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:298)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:268)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:289)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:256)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:703)
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:416)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:370)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:389)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:342)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:229)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:668)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: notification is not mapped
    at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:189)
    at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:109)
    at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:95)
    at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:331)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3633)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3522)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:278)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:206)
    ... 58 more

What is the issue here? Also please note in MySQL query I used both delete_timestamp and deleteTimestamp but both ended up in the same error.

Answer 1

In Hibernate (and JPA), the mapping is to the class, that is, Notification. HQL works using your entity classes, and is case sensitive.

With this in mind, your HQL query

from notification where delete_timestamp IS NULL

Should be

from Notification where deleteTimestamp IS NULL
     ^                  ^ 
     |---> class        |---> attribute in your class