Duplicate entry for key

[Rooftop]

Hello,

When i save this class.

@Entity
@RooEntity
@RooJavaBean
@RooToString
public class Productgroup {

    @NotNull
    @Size(max = 30)
    private String name;

    @OneToMany(cascade = CascadeType.ALL)
    private Set<Prefix> prefixes = new HashSet<Prefix>();

    @OneToMany(cascade = CascadeType.ALL)
    private Set<Postfix> postfixes = new HashSet<Postfix>();
}

I get a the following error.

Caused by: java.sql.BatchUpdateException: Duplicate entry '1' for key 2
at com.mysql.jdbc.PreparedStatement.executeBatchSeria lly(PreparedStatement.java:1666)
at com.mysql.jdbc.PreparedStatement.executeBatch(Prep aredStatement.java:1082)
at org.apache.commons.dbcp.DelegatingStatement.execut eBatch(DelegatingStatement.java:297)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch( BatchingBatcher.java:48)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(Ab stractBatcher.java:246)
... 107 more

This only occurs when i use hibernate with mysql not when i use openjpa with mysql. To reproduce execute the attached script, run wepapp, create some prefixes and postfixes, create two productgroups that have a relation to the same prefix or postfix.

Kind regards,

Ronald Vermeire