Question

I have three entities: User, Team, and TeamInvite. Each User has one Team. Each User can invite other Users to their Team by creating a TeamInvite. When a TeamInvite is accepted, each User’s *Team* is updated. TeamInvites do not affect Users, just their Teams.

@Entity
public class Team extends Model {
    @OneToOne
    public User user;

    @ManyToMany(cascade=CascadeType.ALL)   //I've also tried CascadeType.PERSIST
    public List<User> team = new ArrayList<User>();
}

@Entity
public class TeamInvite extends Model {
    @ManyToOne
    public User inviter;

    @ManyToOne
    public User invitee;

    public void fulfill() {
        Team team = Team.forUser(inviter);
        team.team.add(invitee);
        team.save();    //error gets thrown here

        team = Team.forUser(invitee);
        team.team.add(inviter);
        team.save();

        delete();
    }
}

When TeamInvite.fulfill() gets called, I get the following error:

PersistenceException occured : org.hibernate.exception.SQLGrammarException: could not insert collection: [models.Team.team#2]

play.exceptions.JavaExecutionException: org.hibernate.exception.SQLGrammarException: could not insert collection: [models.Team.team#2]
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:231)
    at Invocation.HTTP Request(Play!)
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not insert collection: [models.Team.team#2]
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1214)
    ...
Caused by: org.hibernate.exception.SQLGrammarException: could not insert collection: [models.Team.team#2]
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    at org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1243)
    at org.hibernate.action.CollectionUpdateAction.execute(CollectionUpdateAction.java:81)
    ...
Caused by: org.h2.jdbc.JdbcSQLException: Duplicate column name "TEAM_ID"; SQL statement:
insert into Team_dp_user (Team_id, team_id) values (?, ?) [42121-149]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:327)
    at org.h2.message.DbException.get(DbException.java:167)
    ...

I copied my annotation structure from the Yabe demo (Posts have a Set of Tags). Anybody know what I’m doing wrong?

Answer 1

I guess the inverse side of Team.team relationship is named User.team as well. If so, you have a collision between columns names in the join table, because their default form is propertyName + "_id".

So, you need to change one of the property names, or override default column names with @JoinTable.