SQL 查询 之 union ,case ,group
摘要：
union alluse myDBSELECT '大于20' as scope,count(*) as 人数FROM student where age>=60union all SELECT '小于20' as scope ,count(*) as 人数FROM student where ag... 阅读全文
posted @ 2014-12-17 16:47 @冰糖 阅读(275) 评论(0) 推荐(0) 编辑
