How to define index by several columns in hibernate entity?

Question

Morning.

I need to add indexing in hibernate entity. As I know it is possible to do using @Index annotation to specify index for separate column but I need an index

Answer 1

Please try the following:

@Entity
@org.hibernate.annotations.Table(appliesTo = House.TABLE_NAME,
    indexes = {
            @Index(name = "IDX_XDN_DFN",
                    columnNames = {House.XDN, House.DFN}
            )
    }
)
@Table(name="house")
public class House {
    ...
}

Note that this should also allow you to create a multi-column index (based on the index name):

@Index(name = "index1")
public String getFoo();

@Index(name = "index1")
public String getBar();

P.S.: What version of Hibernate are you using BTW? What database/dialect?

Answer 2

You have to have hibernate.hbm2ddl.auto set to create in persistence.xml. When set to update hibernate won't create indexes.

hibernate.hbm2ddl.auto = create

Answer 3

You'd better go with a composite primary key.

This article explains how to do it with JPA annotations. It uses @Embeddable and @EmbeddedId