6.在WHERE中使用between...and...
用于区间值的条件判断(包含边界值)
//查询工资在2000(包含)到3000(包含)之间的员工信息
select empno,ename,sal
from emp
where sal>=2000 and sal<=3000;
//采用between...and...实现
select empno,ename,sal
from emp
where sal between 2000 and 3000;
//查询2081年入职的，工资在2000和3000之间(包含)
//的员工信息
select empno,ename,sal
from emp
where to_char(hiredate,'yyyy')='2081'
and sal between 2000 and 3000;
//查询2081到2083年之间入职的员工信息
select empno,ename,sal
from emp
where to_char(hiredate,'yyyy')>='2081'
and to_char(hiredate,'yyyy')<='2083'