Holocron: Hibernate Road 2

Guardando Collecciones, @ElementCollection

Una alternativa para no tener que crear varios campo de address, es crear un campo de tipo lista de Address, o una Colección, esto se logra con la anotacion @ElementCollection

UserDetails.java
...@Entity
@Table (name="USER_DETAILS")
public class UserDetails {
    @Id @GeneratedValue(strategy=GenerationType.AUTO)
    private int userId;
    private String userName;
    @Temporal (TemporalType.DATE)
    private Date joinedDate;
    @ElementCollection
    private Set<Address> listOfAddresses = new HashSet();
    @Lob
    private String description;
...

El programa de prueba HibernateTest.java, que prepara y carga los campos de las entidades quedaría de la siguiente manera.

public class HibernateTest {

    public static void main(String[] args) {
       Address addr1 = new Address();
       addr1.setStreet("calle 10");
       addr1.setCity("Mexico");
       addr1.setState("DF");
       addr1.setPinCode("32123");

       Address addr2 = new Address();
       addr2.setStreet("Miguel Hidalgo");
       addr2.setCity("San Miguel de Allende");
       addr2.setState("Guanajuato");
       addr2.setPinCode("00011");

       Address officeAddr = new Address();
       officeAddr.setStreet("Paseo de la Reforma");
       officeAddr.setCity("Mexico");
       officeAddr.setState("D.F");
       officeAddr.setPinCode("01223");

       UserDetails userDetails = new UserDetails();
       UserDetails userDetails2 = new UserDetails();

       userDetails.setUserName("Primer Usuario");
       userDetails.setJoinedDate(new Date());
       userDetails.setDescription("Primer Usuario Descripcion");
       userDetails.getListOfAddresses().add(addr1);
       userDetails.getListOfAddresses().add(officeAddr);

       userDetails2.setUserName("Segundo Usuario");
       userDetails2.getListOfAddresses().add(addr2);

       SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
       Session session = sessionFactory.openSession();
       session.beginTransaction();
       session.save(userDetails);
       session.save(userDetails2);
       session.getTransaction().commit();
       session.close();
       //sessionFactory.close();
    }

Al ejecutar esta prueba, Hibernate en la consola reporta crear dos tablas, ademas de la de sequencia.

...
Hibernate: drop table if exists hibernate_sequence
...
Hibernate: drop table if exists USER_DETAILS
Hibernate: drop table if exists UserDetails_listOfAddresses
Hibernate: create table hibernate_sequence (next_val bigint) engine=MyISAM
...
Hibernate: insert into hibernate_sequence values ( 1 )
Hibernate: create table USER_DETAILS (userId integer not null, description longtext, joinedDate date, userName varchar(255), primary key (userId)) engine=MyISAM
Hibernate: create table UserDetails_listOfAddresses (UserDetails_userId integer not null, city varchar(255), pinCode varchar(255), state varchar(255), street varchar(255)) engine=MyISAM
Hibernate: alter table UserDetails_listOfAddresses add constraint FK6wx73ocb6j0mymo1jkcv0o3wm foreign key (UserDetails_userId) references USER_DETAILS (userId)
...

Podemos ver que crea la llave foranea.

Tabla USER_DETAILS

userId	description	joinedDate	userName
1	Primer Usuario Descripcion	2018-05-28	Primer Usuario
2	NULL	NULL	Segundo Usuario

Tabla UserDetails_listOfAddresses

UserDetails_userId	city	pinCode	state	street
1	Mexico	32123	DF	calle 10
1	Mexico	01223	D.F	Paseo de la Reforma
2	San Miguel de Allende	00011	Guanajuato	Miguel Hidalgo

Podemos interpretar que para el usuario Id 1 le corresponden 2 Address, mientras que para el usuario id 2, solo un Address.

@OneToOne, con Entidades UserDetails y Vehicle

Dejando atrás las Colecciones, haremos una relación de dos entidades, UserDetails y Vehicle. Para esto se agregara una propiedad vehicle la cual es una entidad por si misma, y para hacer la relación de entidades por medio de la anotación @OneToOne y @JoinColumn.

UserDetails.java

…

@Entity

@Table (name="USER_DETAILS")

public class UserDetails {

@Id @GeneratedValue(strategy=GenerationType.AUTO)

private int userId;

private String userName;

@OneToOne

@JoinColumn(name="VEHICLE_ID")

private Vehicle vehicle;

…Setters y Getters

…

La entidad vehicle, tiene una llave con autogeneración de secuencia.

Vehicle.java

@Entity

public class Vehicle {

@Id @GeneratedValue(generator="vehicle-gen",strategy=GenerationType.AUTO)

@GenericGenerator(name="vehicle-gen",strategy="sequence",

parameters = {

@Parameter(name="sequence_name", value="seq_vehicle") }

)

private int vehicleId;

private String vehicleName;

setters y getters

…

El programa HibernateTest.java carga e inicializa con valores de prueba estas dos entidades.

HibernateTest.java

public class HibernateTest {

public static void main(String[] args) {

UserDetails userDetails = new UserDetails();

userDetails.setUserName("Primer Usuario");

UserDetails userDetails2 = new UserDetails();

userDetails2.setUserName("Segundo Usuario");

Vehicle vehicle = new Vehicle();

vehicle.setVehicleName("Carrito");

Vehicle vehicle2 = new Vehicle();

vehicle2.setVehicleName("Super Auto");

userDetails.setVehicle(vehicle);

userDetails2.setVehicle(vehicle2);

SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();

Session session = sessionFactory.openSession();

session.beginTransaction();

session.save(userDetails);

session.save(vehicle);

session.save(userDetails2);

session.save(vehicle2);

session.getTransaction().commit();

session.close();

//sessionFactory.close();

}

La ejecución de HibernateTest.java muestra en consola por parte de Hibernate como crea las tablas y sus tablas de secuencias. Se observa que crea para userdetails una llave foránea hacia vehicle.

…

Hibernate: drop table if exists hibernate_sequence

may 30, 2018 11:58:21 AM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection

INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@f80945f] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.

Hibernate: drop table if exists seq_vehicle

Hibernate: drop table if exists USER_DETAILS

Hibernate: drop table if exists Vehicle

Hibernate: create table hibernate_sequence (next_val bigint) engine=MyISAM

may 30, 2018 11:58:21 AM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection

INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@22ffa91a] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.

Hibernate: insert into hibernate_sequence values ( 1 )

Hibernate: create table seq_vehicle (next_val bigint) engine=MyISAM

Hibernate: insert into seq_vehicle values ( 1 )

Hibernate: create table USER_DETAILS (userId integer not null, userName varchar(255), VEHICLE_ID integer, primary key (userId)) engine=MyISAM

Hibernate: create table Vehicle (vehicleId integer not null, vehicleName varchar(255), primary key (vehicleId)) engine=MyISAM

Hibernate: alter table USER_DETAILS add constraint FKqweooss4hgrydsdo0xj7m6p40 foreign key (VEHICLE_ID) references Vehicle (vehicleId)

…

La Tabla vehicle

vehicleId	vehicleName
1	Carrito
2	Super Auto

La table UserDetails

userId	userName	VEHICLE_ID
1	Primer Usuario	1
2	Segundo Usuario	2

@OneToMany

Establescamos una relación uno a muchos, es decir, por un usuario, Habra muchos vehiculos.

UserDetails.java

@Entity

@Table (name="USER_DETAILS")

public class UserDetails {

@Id @GeneratedValue(generator="vehicle-gen",strategy=GenerationType.AUTO)

@GenericGenerator(name="vehicle-gen",strategy="sequence",

parameters={@Parameter(name="sequence_name",value="seq_vehicle")}

)

private int userId;

private String userName;

@OneToMany

private Collection<Vehicle> vehicle = new ArrayList<Vehicle>();

Al ejecutar HibernateTest.java, en la consola hibernate reporta que crea una table llamada USER_DETAILS_Vehicle que hace un mapeo entre los registros de la table UserDetails y Vehicle.

…

Hibernate: drop table if exists hibernate_sequence

…

Hibernate: drop table if exists seq_vehicle

Hibernate: drop table if exists USER_DETAILS

Hibernate: drop table if exists USER_DETAILS_Vehicle

Hibernate: drop table if exists Vehicle

Hibernate: create table hibernate_sequence (next_val bigint) engine=MyISAM

…

Hibernate: insert into hibernate_sequence values ( 1 )

Hibernate: create table seq_vehicle (next_val bigint) engine=MyISAM

Hibernate: insert into seq_vehicle values ( 1 )

Hibernate: create table USER_DETAILS (userId integer not null, userName varchar(255), primary key (userId)) engine=MyISAM

Hibernate: create table USER_DETAILS_Vehicle (UserDetails_userId integer not null, vehicle_vehicleId integer not null) engine=MyISAM

Hibernate: create table Vehicle (vehicleId integer not null, vehicleName varchar(255), primary key (vehicleId)) engine=MyISAM

Hibernate: alter table USER_DETAILS_Vehicle add constraint UK_7fhk3kle7eb0p5vqydj1eugt7 unique (vehicle_vehicleId)

Hibernate: alter table USER_DETAILS_Vehicle add constraint FKd6kp2c4oltmpsg6g9d8u15ymw foreign key (vehicle_vehicleId) references Vehicle (vehicleId)

Hibernate: alter table USER_DETAILS_Vehicle add constraint FKbdrxqw3j8dovf9npdkrfkpc3u foreign key (UserDetails_userId) references USER_DETAILS (userId)

…

Hibernate: select next_val as id_val from seq_vehicle for update

Hibernate: update seq_vehicle set next_val= ? where next_val=?

Hibernate: select next_val as id_val from seq_vehicle for update

Hibernate: update seq_vehicle set next_val= ? where next_val=?

Hibernate: select next_val as id_val from hibernate_sequence for update

Hibernate: update hibernate_sequence set next_val= ? where next_val=?

Hibernate: select next_val as id_val from hibernate_sequence for update

Hibernate: update hibernate_sequence set next_val= ? where next_val=?

Hibernate: insert into USER_DETAILS (userName, userId) values (?, ?)

Hibernate: insert into Vehicle (vehicleName, vehicleId) values (?, ?)

Hibernate: insert into USER_DETAILS_Vehicle (UserDetails_userId, vehicle_vehicleId) values (?, ?)

Tabla Vehicle

vehicleId	vehicleName
1	carrito
2	Audi

Table UserDetails

userId	userName
1	Primer Usuario
2	Segundo Usuario

Table USER_DETAILS_Vehicle

UserDetails_userId	vehicle_vehicleId
1	1
1	2

@OneToMany @JoinColumn(name=”VEHICLE_ID”)

Ahora establescamos una relacion uno a muchos, es decir, por un usuario, Habra muchos vehiculos.
pero con un campo extra sin necesidad de crear una tabla extra de relación.

UserDetails.java

@Entity

@Table (name="USER_DETAILS")

public class UserDetails {

@Id @GeneratedValue(generator="vehicle-gen",strategy=GenerationType.AUTO)

@GenericGenerator(name="vehicle-gen",strategy="sequence",

parameters={@Parameter(name="sequence_name",value="seq_vehicle")}

)

private int userId;

private String userName;

@OneToMany

@JoinColumn(name="VEHICLE_ID")

private Collection<Vehicle> vehicle = new ArrayList<Vehicle>();

setters y getters…

Las Anotaciones @OneToMany, y @JoinColumn se encargan de hacer esta relación.

HibernateTest.java cargará datos a userDetail y vehicle, al correrlo, hibernate reporta en la consola

…

Hibernate: drop table if exists hibernate_sequence

may 30, 2018 5:41:34 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection

INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@424ebba3] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.

Hibernate: drop table if exists seq_vehicle

Hibernate: drop table if exists USER_DETAILS

Hibernate: drop table if exists Vehicle

Hibernate: create table hibernate_sequence (next_val bigint) engine=MyISAM

may 30, 2018 5:41:34 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection

INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@4bff64c2] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.

Hibernate: insert into hibernate_sequence values ( 1 )

Hibernate: create table seq_vehicle (next_val bigint) engine=MyISAM

Hibernate: insert into seq_vehicle values ( 1 )

Hibernate: create table USER_DETAILS (userId integer not null, userName varchar(255), primary key (userId)) engine=MyISAM

Hibernate: create table Vehicle (vehicleId integer not null, vehicleName varchar(255), VEHICLE_ID integer, primary key (vehicleId)) engine=MyISAM

Hibernate: alter table Vehicle add constraint FK1rpisx3grg2fqb9qg9ioj8kvv foreign key (VEHICLE_ID) references USER_DETAILS (userId)

may 30, 2018 5:41:34 PM org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSources

INFO: HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@2101b44a'

Wed May 30 17:41:35 CDT 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.