摘要: 一、常用关键词:1.distinct:过滤重复select distinct create_user_name from bms_project; 此种情况下,就要用到distinct过滤掉重复的。2.count: 统计select count(*) from bms_project; 查询bms_... 阅读全文
posted @ 2014-11-23 20:36 S-Ping 阅读(109) 评论(0) 推荐(0) 编辑