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9.0

Unique constraint on two fields of a table with EJB3

Asked by serrutom in Enterprise Java Beans (EJB), Java Programming Language, J2EE

Tags: ejb, unique, constraint, database

Is it possible to put a unique constraint on an entity based on two or more fields?

I have a company entity which has a code and name field. It should not be possible to add a second database entry with the same code-name combination.
But it should be possible to a two companies with the same name and a different code.

For example:

id: 1
code: xxx
name: company1

id: 2
code: xxx
name: company2

id: 3
code: yyy
name: company1

The entities above are allowed, but the entity below should be rejected when it is added.

id: 4
code: xxx
name: company1

My entity looks like this right now:

Get your answer NOW

         
             @Entity
@Table(name = "COMPANY", uniqueConstraints = { @UniqueConstraint(columnNames = { "code" }), @UniqueConstraint(columnNames = { "name" }) })
public class Company {
     ...
}

20091111-EE-VQP-89 - Hierarchy / EE_QW_3_20080625

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Unique constraint on two fields of a table with EJB3

Asked by serrutom in Enterprise Java Beans (EJB), Java Programming Language, J2EE

Tags: ejb, unique, constraint, database

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