Using Hibernate, but tables are not saved

[Henrik Engert]

Hi,

I am using Hibernate 3 with HSQLDB.

I have the following Java Bean:

public class Pilot extends Person implements Serializable {
    private long id;
    private Radio radio;
 
 
    public Pilot(String firstname, String lastname) {
        super(firstname, lastname);
    }
 
 
    public Pilot(String firstname, String lastname, Radio radio) {
        super(firstname, lastname);
        this.radio = radio;
    }
 
    public Radio getRadio() {
        return radio;
    }
 
    public void setRadio(Radio radio) {
        this.radio = radio;
    }
 
    public long getId() {
        return id;
    }
 
    public void setId(long id) {
        this.id = id;
    }
 
 
    public String toString() {
        return id + " " + getFirstname() + " " + getLastname();
    }
}

Mapping file looks like this:

<?xml version="1.0" encoding="utf-8"?>
        <!DOCTYPE hibernate-mapping
                PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
                "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="model.Pilot" table="PILOT">
        <id name="id" type="long" column="id">
            <generator class="native"/>
        </id>
 
        <property name="firstname" column="firstname" type="string"/>
 
        <property name="lastname" column="lastname" type="string"/>
 
        <one-to-one name="radio" class="model.Radio" constrained="false"/>
        
    </class>
</hibernate-mapping>

Hibernate configuration looks like this:

<?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>
 
        <property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
        <property name="connection.url">jdbc:hsqldb:file:.\data\F3C</property>
        <property name="connection.username">sa</property>
        <property name="connection.password"></property>
 
        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>
 
        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.HSQLDialect</property>
 
        <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>
 
        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
 
        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>
 
        <!-- Drop and re-create the database schema on startup-->
        <property name="hbm2ddl.auto">update</property>       
 
        <mapping resource="model/pilot.hbm.xml"/>
        <mapping resource="model/radio.hbm.xml"/>
 
    </session-factory>
 
</hibernate-configuration>

I then use a DAO to insert and retreive data. The insert seems to work since I do get back an id of the row inserterted into the PILOT table. But once I try to retrieve the inserted row I get the follwing error:

java.lang.Exception: PILOT is not mapped [from PILOT where id = :id]

It's like the tables are not created.

Can anybody help me?

Thanks.
[ February 06, 2007: Message edited by: Henrik Engert ]

[Henrik Engert]

Solved the problem with this line:

Query q = getSession().createQuery("from Pilot where id = :id");

Changed from PILOT to Pilot.....

BUT, why does the data not persist in the database when I restart the application? If you start the app again with a SELECT (Query q = getSession().createQuery("from Pilot where id = :id") then the data is not there?!

[Mark Spritzler]

You are losing the database data because you are using Hypersonic and using it as an in-memory database, so as soon as you close it, the data goes bye-bye. Try using MySql as a database. Hypersonic is good for testing your app, but not really used for production, when you really want your data to be saved for the long haul.

Mark

[Gregg Bolinger]

Ahh, come on Mark. HSQLDB is great for development purposes. You just need to know how to kick it off correctly. I have an ant script for starting and stopping an HSQLDB server.

<target name="hsqldb.start">
        <echo message="Starting hsqldb" />
        <java fork="true" dir="${basedir}" classname="org.hsqldb.Server">
            <classpath >
                <path refid="libraries" />
            </classpath>
            <arg value="-database.0"/>
            <arg value="db/raidscheduler-db" />
            <arg value="-dbname.0" />
            <arg value="raidscheduler" />
        </java>
</target>
 
<target name="hsqldb.shutdown">
<sql driver="org.hsqldb.jdbcDriver" url="jdbc:hsqldb:hsql://localhost/raidscheduler" userid="sa" password="">
    <classpath >
        <path refid="libraries" />
    </classpath>
    SHUTDOWN
</sql>
</target>

Now, since it starts in server mode, it will be persisted between startups. Here is my dataSource for development. I am using Spring, but you should get the general idea.

<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName">
<value>org.hsqldb.jdbcDriver</value>
</property>
<property name="url">
<value>jdbc:hsqldb:hsql://localhost/raidscheduler</value>
</property>
<property name="username">
<value>sa</value>
</property>
<property name="password">
<value></value>
</property>
</bean>

And yes, I am using Hibernate on this project and it works great. Of course, this database is quite volitile as I am using the schemaexport ant task to generate my DDL from my annotated classes.

[Henrik Engert]

Thanks.

I did suspect that I was running in memory only, but I thought as soon as I added the "file" in the hibernate.cfg.xml file that it would actually write the data to file.

I am new to all this with Hibernate. I really don't want to use MySQL for my ultra small application that I am trying do write. But I must say that MySQL is far easier to maintain.

I did get Hibernate to work with Derby instead.

Thanks again.
[ February 07, 2007: Message edited by: Henrik Engert ]

[Mark Spritzler]

Don't get me wrong Gregg, I use Hypersonic a lot for development, that is what I really meant when I said testing, I included development in my term, because I was using the term broadly and not the IT specific term.

Let me go answer your other thread.

Mark