1、查询工作地点在纽约或波士顿的员工信息select emp.* from emp where deptno in (select deptno from dept where dept.loc=‘NEW YORK’ or dept.loc=‘BOSTON’) 2、查询员工的工资等级(emp,salgrade) select emp., case when sal>=700 and sal<=1200 then 1 when sal>=1201 and sal<=1400 then 2 when sal>=1401 and sal<=2000 then 3 when sal>=2001 and sal<=3000 then 4 when sal>=3001 and sal<=9999 then 5 else 0 end 薪资等级 from emp 或者 select emp.,salgrade.grade from emp,salgrade where salgrade.losal
用的也是oracle自带的表和数据
