mysql关联删除
传统方式：
delete from t_base_dl_price where id in (
select a.id from t_base_dl_price a left join t_base_dl_info b on a.userCode = b.user_code
where not (b.factory_name = '武汉'));
高性能方式：
DELETE a FROM t_base_dl_price a left JOIN t_base_dl_info b ON a.userCode = b.user_code
WHERE not (b.factory_name = '武汉' );