025排序操作

select .. from .. order by 字段 asc/desc

select empno, ename, sal from emp order by sal asc;

多個字段排序

查詢員工的編號、姓名、薪資，按照薪資升序排列，如果薪資相同的，再按照姓名升序排列。

select empno,ename,sal from emp order by sal asc, ename asc;
select empno,ename,sal from emp order by 3 asc, 2 asc;

select ename,job,sal from emp where job in ('MANAGER','SALESMAN') order by sal desc;

select ename,job,sal*12 as yearsal from emp where job in ('MANAGER','SALESMAN') order by yearsal asc;

說明order在select后執行，優先級低

select ename,job,sal*12 as yearsal from emp where job in ('MANAGER','SALESMAN') order by sal asc;

按原始名字sal排序也可