Ww0WpR1J

1CREATE TABLE IF NOT EXISTS engines (
2  id    SERIAL PRIMARY KEY,
3  model VARCHAR(25) UNIQUE NOT NULL,
4  power INTEGER            NOT NULL
5);
6
7CREATE TABLE IF NOT EXISTS cars (
8  id        SERIAL PRIMARY KEY,
9  mark      VARCHAR(25) NOT NULL,
10  model     VARCHAR(25) NOT NULL,
11  engine_id INTEGER     NOT NULL,
12  FOREIGN KEY (engine_id) REFERENCES engines (id)
13);
14	
15ERROR: duplicate key value violates unique constraint "engines_model_key"
16  Detail: Key (model)=(test) already exists.
17	
18<hibernate-mapping xmlns="http://www.hibernate.org/xsd/hibernate-mapping">
19
20    <class name="ru.javavision.model.Car" table="cars">
21        <id name="id" column="id">
22            <generator class="identity"/>
23        </id>
24        <property name="mark" column="mark"/>
25        <property name="model" column="model"/>
26
27        <!--Прикрепляем сущьность двигателя-->
28        <many-to-one name="engine" column="engine_id"
29                     class="ru.javavision.model.Engine"
30                     cascade="save-update" not-null="true"/>
31    </class>
32</hibernate-mapping>
33	
34<hibernate-mapping xmlns="http://www.hibernate.org/xsd/hibernate-mapping">
35
36    <class name="ru.javavision.model.Engine" table="engines">
37        <id name = "id" type = "int" column = "id">
38            <generator class="identity"/>
39        </id>
40        <property name="model" column="model"/>
41        <property name="power" column="power"/>
42    </class>
43</hibernate-mapping>
44	
45private final SessionFactory factory = ...;
46
47public void create(@NotNull final Car car) {
48
49    try (final Session session = factory.openSession()) {
50
51        session.beginTransaction();
52
53        session.save(car);
54
55        session.getTransaction().commit();
56    }
57}