Hibernate 3 ebook pdf
The insertion of a person and a geek issues the following statements to the database: Hibernate: call next value for hibernate_sequence Hibernate: insert into T_person (first_name, last_name, ID) values (?,?,?,?) Hibernate: call next value for hibernate_sequence Hibernate: insert into T_geek (first_name, last_name, FAV_prog_lang, ID) values.
As a second step the run method constructs a ServiceRegistry that uses the previously loaded configuration.
As this is not always the preferred way to handle relationships between entities, one can also select only specific operations: The example above demonstrates how to configure the mapping such that only calls to save saveOrUpdate and refresh (re-reads the state of the given object.Inheritance An interesting feature of O/R mapping solutions like Hibernate is the usage of inheritance.We can also see the three columns ID, first_name and last_name of the table T_person as well as the definition of the primary key (here: ID).These statements create the new tables T_project as well as T_geeks_projects.As we want to commit our transactions in the example code pharmacotherapy principles and practice pdf on our own, we also define the H2 specific configuration option autocommitoff.The following code demonstrates how to obtain a new transaction from the session and how to start and commit it: try Transaction transaction tTransaction gin.It allows developers to map the object structures of normal Java classes to the relational structure of a database.Book 2005, iSBN: (Print) (Online get Access.The table T_geek is completely filled by one insertion and contains all values of an instance of Geek: sql select * from t_person; ID first_name last_name 1 Homer Simpson sql select * from t_geek; ID first_name last_name FAV_prog_lang 3 Gavin Coffee Java 4 Thomas Micro.H2.Driver 1 thread CacheProvider true true create As we see from the example above, the configuration file defines a set of properties for the session factory.Using on of the two configurations above, the code to store a person together with its id card can be rewritten to the following one: Person person new Person tFirstName Homer tLastName Simpson IdCard idCard new IdCard tIdNumber 4711 tIssueDate(new Date tIdCard(idCard ve(person Instead.In case you also want to see the values that are bound to the parameters of the PreparedStatement, you can set the logging level for the logger org.Next to the value native shown above, Hibernate supports a long list of different strategies.In order to model such a relation we add the class Phone to our model: public class Phone private Long id; private String number; private Person person; public Long getId return id; public void setId(Long id) id; public String getNumber return number; public void setNumber(String.To use this strategy for the above use case, the mapping file can be rewritten like the following one: The XML element union-subclass provides the name of the entity (Geek) as well as the name of the separate table (T_geek) as attributes.A subtle difference between both implementations is the fact that the save methods returns the created identifier of the new entity: Long personId (Long) ve(person This is helpful when writing for example server side code that should return this identifier to the caller of the.Sql select * from t_person; ID person_type first_name last_name FAV_prog_lang 1 rson Homer Simpson null 2 ek Gavin Coffee Java 3 ek Thomas Micro C# 4 ek Christian Cup Java As discussed above, the column ben 10 omniverse game 3ds person_type stores the type of the instance whereas the column.Next to the usual identifier (id) that is generated using a sequence and the field number this definition also contains out the many-to-one element.The following sample codes shows how to store instances of type Geek in the database: gin Geek geek new Geek tFirstName Gavin tLastName Coffee ve(geek geek new Geek tFirstName Thomas tLastName Micro ve(geek geek new Geek tFirstName Christian tLastName Cup ve(geek mmit Executing the code.
Therefore each thread in the application should work with its own session that it obtains from the session factory.
To understand these different types of relationships a little better, we will investigate them in the following.