JPA Association Without Foreign Key

Is it possible to create a ManyToOne association without creating a JPA foreign key in the database?

The tables are owned by a different system and populated asynchronously. So we cannot have FK in the database. There is still, almost always, in the end an attitude.

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumns({
        @JoinColumn(name="`Order Type`", referencedColumnName = "`Order Type`", insertable = false, updatable = false),
        @JoinColumn(name="`Order No`", referencedColumnName = "`No`", insertable = false, updatable = false)
}, foreignKey = @javax.persistence.ForeignKey(value = ConstraintMode.NO_CONSTRAINT))
private OrderHeader orderHeader;

      

        
        
        
      

    

The problem is that JPA SchemaUpdate is trying to add FK even though ConstraintMode.NO_CONSTRAINT

[error] ohthSchemaUpdate - unable to add foreign key constraint

and we could ignore that if that didn't make the rest of the statements fail

[error] ohthSchemaUpdate - operations are not allowed after the statement is closed.

We are on hibernate-entitymanager 4.3.7.Final and JPA 2.1.