hibernate有关联关系删除子表时可能会报错，可以用个clear避免错误

    //清除子表数据

    public SalesSet removeSalesSetDistributor(SalesSet salesSet ){

        List<SalesSetDistributor> salesSetDistributorList = salesSet.getSalesSetDistributors();

        deleteAll(salesSetDistributorList);

        salesSetDistributorList.clear();

        save(salesSet);

        return salesSet;

    }