IN操作符
select * from scott.emp where empno=7369 or empno=7566 or empno=7788 or empno=9999；
select * from scott.emp where empno IN （7369,7566,7788,9999）;
select * from scott.emp where NOT IN （7369,7566,7788,9999）; 相反
复习：
找出佣金高于薪金的百分之60的员工。
select * from scott.emp where comm>sal*0.6；
