oracle数据库方面的知识到今天已经整理了12篇。当然，这不是终点，这只是一个开始，希望我写的文章可以帮助更多初学数据库的童鞋快速上手，如果你觉得文章对你有帮助，那么恭喜你已经入门了，数据库里面的知识有很多，多到让你可以从入门到放弃。那么你可以通过该篇文章快速入门oracle中关于查询的各种姿势：
oracle课程大纲：
如果你想拿一些数据库的习题练习，下面的例子或许是一个不错的选择！
--题目
--1、新员工王小明，员工编号是11，性别是男，年龄30，岗位编号是5，岗位是测试工程师，部门编号是3，
--部门名称是测试部，薪水6000(基本工资2800，奖金3200);
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
1题答案
--薪水表
insert into salary(salaryid,employid,basesalary,bonussalary) values(11,11,2800,3200);
commit;
--员工表
insert into employ(ename,employid,sex,age,stationid,deptid) values('王小明',11,'男',30,5,3);
commit;
--部门表
insert into dept(deptid,deptname) values(3,'测试部');
commit;
--岗位表
insert into station values(5,'测试工程师');
commit;
--2、王小明试用期过了，表现非常好，公司决定给他基本工资调薪10%，奖金调15%;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
update salary
set basesalary = basesalary + basesalary * 0.1,
bonussalary = bonussalary + bonussalary * 0.15
where salaryid = 11;
commit;
--3、查询测试部门最高薪水，最低薪水，平均薪水，显示最高薪水，最低薪水，平均薪水;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select t2.deptname 部门,
max(t3.basesalary + t3.bonussalary) 最高薪,
min(t3.basesalary + t3.bonussalary) 最低薪,
avg(t3.basesalary + t3.bonussalary) 平均薪资
from employ t1, dept t2, salary t3
where t1.employid = t3.employid
and t2.deptid = t1.deptid
and t2.deptid = 3
group by t2.deptname;
--4、查询所有部门的最高薪水，最低水，平均薪水，显示部门，最高薪水，最低薪水，平均薪水,并按部门名升序排序;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select t3.deptid 部门名称,t3.deptname 部门名字,
max(t2.basesalary+t2.bonussalary) 最高薪,
min(t2.basesalary+t2.bonussalary) 最低薪,
avg(t2.basesalary+t2.bonussalary) 平均薪资
from employ t1, salary t2, dept t3 where t1.employid=t2.employid and t1.deptid=t3.deptid
group by t3.deptid,t3.deptname order by t3.deptname asc;
--5、统计测试部门有多少员工，显示员工数;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select t2.deptname 部门名字, count(t1.employid) 人数
from employ t1, dept t2
where t1.deptid = t2.deptid
and t2.deptid =
group by t2.deptname;
--6、统计所有部门员工数，并按部门进行升序排序，显示部门，员工数;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select t2.deptname 部门名字, count(t1.employid) 员工总数
from employ t1, dept t2
where t1.deptid = t2.deptid
group by t2.deptname
order by t2.deptname asc;
--7、查询所有姓王的所有员工信息;
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select *
from employ t1, salary t2, dept t3, station t4
where t1.employid = t2.employid
and t1.deptid = t3.deptid
and t1.stationid = t4.stationid
and t1.ename like '王%'
order by t1.employid;
--8、按部门，性别统计平均薪水;
select t2.deptname 部门名字,
t1.sex 性别,
round(avg(t3.basesalary + t3.bonussalary)) 平均薪水
from employ t1, dept t2, salary t3
where t1.deptid = t2.deptid
and t1.employid = t3.employid
group by t2.deptname, t1.sex;
--9、查询30到40岁的平均薪水;
select t1.ename 姓名, avg(t2.basesalary + t2.bonussalary) 平均薪资
from employ t1, salary t2
where t1.employid = t2.employid
and t1.age between 30 and 40
group by t1.ename;
--10、查询测试部薪水最高的员工，显示员工姓名；
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
select t1.ename 员工姓名,
t2.deptname 部门名字,
max(t3.basesalary + t3.bonussalary) 薪水
from employ t1, dept t2, salary t3
where t1.deptid = t2.deptid
and t1.employid = t3.employid
and t2.deptid = 3
group by t2.deptname, t1.ename;
--11、删除王小明的所有信息
select * from salary; --薪水表
select * from employ; --员工表
select * from dept; --部门表
select * from station; --岗位表
delete from salary where salaryid=11;
delete from employ where ename='王小明';
delete from dept where deptid=3;
delete from station where stationid=5;