Hi all guys,

I'm totally new to Hibernate world so I have a lot to learn. Actually, I'm tryin' to realize the following:

I have two tables: Cars table and Price table made up as follow:

Car:
Integer carId [PK]
String factory
String model
String color

Price
Integer priceId [PK]
Long price
Integer id_car [FK]

The id_auto field of Price table is a foreign key given by the Car table column autoId. So I think I have a one-to-many relation between Car and Price tables.

Now I'm tryin' to achieve three goals:

- First goal: to build up two .hbm.xml files compliant with my situation.
- Second goal: to write two persistent classes, one for each table
- Third goal: to realize a join query whose resultset contains, for each car, all the available information from the two tables: factory, model, color and price or set of prices.

Ok, so ... that's my problem. I'm still stuffed at first goal.
By now, my .hbm.xml files are:

Cars.hbm.xml


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="mapping.Cars" table="CARS">
<id name="id" type="integer">
<column name="ID" />
<generator class="increment" />
</id>
<property name="factory" type="string">
<column name="FACTORY" length="45" not-null="true" />
</property>
<property name="model" type="string">
<column name="MODEL" length="45" not-null="true" />
</property>
<property name="color" type="string">
<column name="COLOR" length="45" not-null="true" />
</property>
</class>
</hibernate-mapping>


Price.hbm.xml:


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="mapping.Price" table="PRICE">
<id name="id" type="integer">
<column name="ID" />
<generator class="increment" />
</id>
<property name="price" type="double">
<column name="PRICE" precision="0" scale="0" />
</property>
<property name="idCar" type="integer">
<column name="ID_CAR" not-null="true" />
</property>
</class>
</hibernate-mapping>



Thank you in advance to any who could help me!!

Best regards
tronky

Hi, the first thing is that you have to decide whether this asso. is supposed to be uni / or bidirectional. I'll give you a example for bidirectional.
But why does the Price Table has the freign key? In my understanding it would make sense to have multiple cars having the same price and not one car with multiple prices.

Anyway:



-- simon --

Hi simonwillnauer, thank you for replying. In my meanings one car model could have multiple price according to various optional you may choose to install. On the other way, I didn't think on the inverse relationship, so I suppose the relation is uni-directional. BTW thank you very much for your aid. I'll try immediatly.

Greetings
tronky