随笔分类 -  SQL

distinct
摘要：distinct关键字用在整个记录行上。 select distinct a,b from (select 'a' a, 'b' b from dualunion allselect 'a' a, 'b' b from dual) t 阅读全文
posted @ 2016-09-22 09:45 letmedown 阅读(163) 评论(0) 推荐(0)
SQL CASE
摘要：SELECT L.id, L.name, L.zero_three_num, L.four_six_num, seven_nine_num, ten_or_more_num, (L.zero_three_num+L.four_six_num+seven_nine_num+ten_or_more_nu... 阅读全文
posted @ 2014-12-26 16:27 letmedown 阅读(110) 评论(0) 推荐(0)