一、多表查询
select a1.ename,a2.dname,a1.sal from emp a1,dept a2 where a1.deptno=a2.deptno order by a1.deptno;
二、分页查询
rownum分页
select * from emp;
显示rownum【oracle分配的】
select a1.*,rownum rn from (select * from emp) al;
select a1.*,rownum rn from (select * from emp) a1 where rownum<=10;
select * from (select a1.*,rownum rn from (select * from emp) a1 where rownum<=10) where rownum>=6;
三、用查询结果创建新表