遇到的小知识

2016-12-30
/^[0-9]*$/
2017-01-04
mysql 字段拼接
 SELECT
concat(area_info,store_address) as store_address,
 li 标签空格占位
2017-01-05
sql 将null转化为0
ifnull(s.good_desc,0) as good_desc,
sql 将左联接
FROM
    shop_store t
        left JOIN
    shop_store_dsr s ON t.store_id = s.store_id AND s.calc_date = '2017-01-04'
WHERE
    t.store_id = 177 ;
2017-01-06
时间推后
Date date=new Date();
Date startDate=DateUtil.addMonth(date,-24);
2017-02-07
清除session的某个属性   removeAttribute


var fuc=function(){
  return 1;
}