Spring – How to configure multiple schemas with Hibernate

hibernatehibernate-criteriahibernate-mappingormspring

We have got a requirement for multiple schemas in Hibernate.

In our project, we need to connect to multiple schemas based on the username and password. But how to configure multiple schemas in Hibernate?

Please let me know if there's a way.

Best Answer

You can specify it by schema element while defining table for your entity.

@Table(name="TABLE_NAME", schema="SCHEMA_NAME")

Else, you can use separate EntityManager pointing to respective schema & then use the same entity, as their structure is similar.

Edit : You can have separate configuration files for each schema & then build SessionFactory from it, below is some pseudo-code for it.

SessionFactory sf_1 = new  Configuration().configure("schema1config.cfg.xml").buildSessionFactory();
SessionFactory sf_2 = new Configuration().configure("schema2config.cfg.xml").buildSessionFactory();

session_1 = sf_1.openSession();  //-- Similarly for other

You can refer this link for further details to map multiple schema, but it isn't hibernate specific.

Related Solutions

Java – Creation timestamp and last update timestamp with Hibernate and MySQL

If you are using the JPA annotations, you can use @PrePersist and @PreUpdate event hooks do this:

@Entity
@Table(name = "entities")    
public class Entity {
  ...

  private Date created;
  private Date updated;

  @PrePersist
  protected void onCreate() {
    created = new Date();
  }

  @PreUpdate
  protected void onUpdate() {
    updated = new Date();
  }
}

or you can use the @EntityListener annotation on the class and place the event code in an external class.

Java – What are the possible values of the Hibernate hbm2ddl.auto configuration and what do they do

From the community documentation:

hibernate.hbm2ddl.auto Automatically validates or exports schema DDL to the database when the SessionFactory is created. With create-drop, the database schema will be dropped when the SessionFactory is closed explicitly.

e.g. validate | update | create | create-drop

So the list of possible options are,

validate: validate the schema, makes no changes to the database.
update: update the schema.
create: creates the schema, destroying previous data.
create-drop: drop the schema when the SessionFactory is closed explicitly, typically when the application is stopped.
none: does nothing with the schema, makes no changes to the database

These options seem intended to be developers tools and not to facilitate any production level databases, you may want to have a look at the following question; Hibernate: hbm2ddl.auto=update in production?

Best Answer

Related Solutions

Java – Creation timestamp and last update timestamp with Hibernate and MySQL

Java – What are the possible values of the Hibernate hbm2ddl.auto configuration and what do they do

Related Topic