随笔分类 -  SQL

SQL--常用操作
摘要：- 删字段： 阅读全文
posted @ 2016-10-25 17:58 盖瑞 阅读(88) 评论(0) 推荐(0)
SQL--查询相同字段的数据
摘要：select city, statefrom state_county_citywhere city in (select city from state_county_city group by city having count(1) >= 2) 阅读全文
posted @ 2016-09-20 14:17 盖瑞 阅读(216) 评论(0) 推荐(0)