相关疑难解决方法(0)

从上面描述的映射中删除元素时遇到问题.这是映射:

@Entity
@Table( name = "foo")
class Foo {

    private List bars;

    @OneToMany
    @OrderColumn( name = "order_index" )
    @JoinTable( name = "foo_bar_map", joinColumns = @JoinColumn( name = "foo_id" ), inverseJoinColumns =  @JoinColumn( name = "bar_id" ) )
    @Fetch( FetchMode.SUBSELECT )
    public List getBars() {
        return bars;
    }
}

插入Bar-instances并保存Foo工作正常,但是当我从列表中删除元素并再次保存时,违反了映射表中bar_id的唯一约束.以下SQL语句是由hibernate发布的,这看起来很奇怪:

LOG:  execute : delete from foo_bar_map where foo_id=$1 and order_index=$2
DETAIL:  parameters: $1 = '4', $2 = '6'
LOG:  execute S_5: update foo_bar_map set bar_id=$1 where foo_id=$2 and order_index=$3
DETAIL:  parameters: …