随笔分类 -  mysql

select之不重复列
摘要：select distinct 列名 from tableOfName;http://www.w3school.com.cn/sql/sql_distinct.asp 阅读全文

posted @ 2014-05-24 15:30 大海520 阅读(113) 评论(0) 推荐(0)

select之group by
摘要：select column_name, aggregate_name(column_name)from table_namewhere column_name operator valuegroup by column_name;理论上是比较耗查询时间。 阅读全文

posted @ 2014-05-24 15:29 大海520 阅读(178) 评论(0) 推荐(0)

select之结果排序
摘要：select column_namefrom table_nameorder by column_name desc(降序), column_name asc(升序); 阅读全文

posted @ 2014-05-24 15:28 大海520 阅读(288) 评论(0) 推荐(0)