mlaaalm

摘要： 1）在select语句中使用条件逻辑 1select ename,sal, 2 case when sal = 4000 then 'OVERPAID' 4 else 'OK' 5 end as status 6from emp ENAME SAL STATUS ---------- ---------- -------... 阅读全文

摘要： Code Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ -->--根目录开始遍历 --向下遍历 select prior a "prior_a" , prior b "prior_b" , prior c "prior_c" ,level ... 阅读全文